diff --git a/ssh/Dockerfile b/ssh/Dockerfile
index b7acbd3d..e38b6bf2 100644
--- a/ssh/Dockerfile
+++ b/ssh/Dockerfile
@@ -42,6 +42,7 @@ RUN \
         colordiff=1.0.22-r0 \
         docker-bash-completion=29.5.3-r0 \
         docker-zsh-completion=29.5.3-r0 \
+        fish \
         gcompat=1.1.0-r4 \
         git=2.54.0-r0 \
         htop=3.5.1-r1 \
@@ -66,7 +67,7 @@ RUN \
         nmap-ncat=7.99-r0 \
         openssh=10.3_p1-r0 \
         openssl=3.5.7-r0 \
-        procps-ng=4.0.6-r0 \
+        procps-ng=4.0.6-r1 \
         pwgen=2.08-r3 \
         pulseaudio-utils=17.0-r7 \
         py3-pip=26.1.2-r0 \
@@ -80,6 +81,7 @@ RUN \
         tmux=3.6b-r0 \
         ttyd=1.7.7-r0 \
         wget=1.25.0-r3 \
+        zellij \
         zip=3.0-r13 \
         zsh-autosuggestions=0.7.1-r0 \
         zsh-syntax-highlighting=0.8.0-r1 \
@@ -93,8 +95,10 @@ RUN \
     \
     && chmod a+x /usr/bin/ha \
     && ha completion bash > /usr/share/bash-completion/completions/ha \
+    && mkdir -p /usr/share/fish/vendor_completions.d \
+    && ha completion fish > /usr/share/fish/vendor_completions.d/ha.fish \
     \
-    && sed -i -e "s#bin/sh#bin/zsh#" /etc/passwd \
+    && sed -i -e "s#/bin/sh#/usr/bin/fish#" /etc/passwd \
     \
     && cp /usr/bin/docker /usr/local/bin/.undocked \
     \
diff --git a/ssh/config.yaml b/ssh/config.yaml
index 13668960..9bf6fd2f 100644
--- a/ssh/config.yaml
+++ b/ssh/config.yaml
@@ -63,7 +63,9 @@ options:
     allow_agent_forwarding: false
     allow_remote_port_forwarding: false
     allow_tcp_forwarding: false
-  zsh: true
+  shell: fish
+  session_backend: zellij
+  zsh: false
   share_sessions: false
   packages: []
   init_commands: []
@@ -79,7 +81,9 @@ schema:
     allow_agent_forwarding: bool
     allow_remote_port_forwarding: bool
     allow_tcp_forwarding: bool
-  zsh: bool
+  shell: list(fish|zsh|bash)
+  session_backend: list(zellij|tmux)
+  zsh: bool?
   share_sessions: bool
   packages:
     - str
diff --git a/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-ssh/run b/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-ssh/run
index b6fa82fc..01ed84e9 100755
--- a/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-ssh/run
+++ b/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-ssh/run
@@ -98,8 +98,9 @@ username=$(bashio::string.lower "${username}")
 # Create user account if the user isn't root
 if [[ "${username}" != "root" ]]; then
 
-    # Create an user account
-    adduser -D "${username}" -s "/bin/zsh" \
+    # Create an user account. Keep the SSH login user on /bin/sh so it can
+    # consistently hand off to the configured root login shell via sudo -i.
+    adduser -D "${username}" -s "/bin/sh" \
         || bashio::exit.nok 'Failed creating the user account'
 
     # Add new user to the wheel group
@@ -107,7 +108,7 @@ if [[ "${username}" != "root" ]]; then
         || bashio::exit.nok 'Failed adding user to wheel group'
 
     # Ensure new user switches to root after login
-    echo 'exec sudo -i' > "/home/${username}/.zprofile" \
+    echo 'exec sudo -i' > "/home/${username}/.profile" \
         || bashio::exit.nok 'Failed configuring user profile'
 fi
 
@@ -129,7 +130,7 @@ if bashio::config.has_value 'ssh.authorized_keys'; then
 fi
 
 # Port
-sed -i "s/Port\\ .*/Port\\ ${port}/" "${SSH_CONFIG_PATH}" \
+sed -i "s/Port\ .*/Port\ ${port}/" "${SSH_CONFIG_PATH}" \
     || bashio::exit.nok 'Failed configuring port'
 
 # SFTP access
@@ -140,16 +141,16 @@ fi
 
 # Allow specified user to log in
 if [[ "${username}" != "root" ]]; then
-    sed -i "s/AllowUsers\\ .*/AllowUsers\\ ${username}/" "${SSH_CONFIG_PATH}" \
+    sed -i "s/AllowUsers\ .*/AllowUsers\ ${username}/" "${SSH_CONFIG_PATH}" \
         || bashio::exit.nok 'Failed opening SSH for the configured user'
 else
-    sed -i "s/PermitRootLogin\\ .*/PermitRootLogin\\ yes/" "${SSH_CONFIG_PATH}" \
+    sed -i "s/PermitRootLogin\ .*/PermitRootLogin\ yes/" "${SSH_CONFIG_PATH}" \
         || bashio::exit.nok 'Failed opening SSH for the root user'
 fi
 
 # Enable password authentication when password is set
 if bashio::config.has_value 'ssh.password'; then
-    sed -i "s/PasswordAuthentication.*/PasswordAuthentication\\ yes/" \
+    sed -i "s/PasswordAuthentication.*/PasswordAuthentication\ yes/" \
         "${SSH_CONFIG_PATH}" \
           || bashio::exit.nok 'Failed to setup SSH password authentication'
 fi
@@ -166,21 +167,21 @@ fi
 
 # Enable Agent forwarding
 if bashio::config.true 'ssh.allow_agent_forwarding'; then
-    sed -i "s/AllowAgentForwarding.*/AllowAgentForwarding\\ yes/" \
+    sed -i "s/AllowAgentForwarding.*/AllowAgentForwarding\ yes/" \
         "${SSH_CONFIG_PATH}" \
           || bashio::exit.nok 'Failed to setup SSH Agent Forwarding'
 fi
 
 # Allow remote port forwarding
 if bashio::config.true 'ssh.allow_remote_port_forwarding'; then
-    sed -i "s/GatewayPorts.*/GatewayPorts\\ yes/" \
+    sed -i "s/GatewayPorts.*/GatewayPorts\ yes/" \
         "${SSH_CONFIG_PATH}" \
           || bashio::exit.nok 'Failed to setup remote port forwarding'
 fi
 
 # Allow TCP forewarding
 if bashio::config.true 'ssh.allow_tcp_forwarding'; then
-    sed -i "s/AllowTcpForwarding.*/AllowTcpForwarding\\ yes/" \
+    sed -i "s/AllowTcpForwarding.*/AllowTcpForwarding\ yes/" \
         "${SSH_CONFIG_PATH}" \
           || bashio::exit.nok 'Failed to setup SSH TCP Forwarding'
 fi
diff --git a/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-user/run b/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-user/run
index 113b8e86..3283a5bb 100755
--- a/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-user/run
+++ b/ssh/rootfs/etc/s6-overlay/s6-rc.d/init-user/run
@@ -7,6 +7,10 @@
 readonly -a DIRECTORIES=(addon_configs addons backup homeassistant media share ssl)
 readonly BASH_HISTORY_FILE=/root/.bash_history
 readonly BASH_HISTORY_PERSISTENT_FILE=/data/.bash_history
+readonly FISH_CONF_D_PATH=/root/.config/fish/conf.d
+readonly FISH_HOME_ASSISTANT_CONF_D_FILE=/root/.config/fish/conf.d/homeassistant.fish
+readonly FISH_HISTORY_FILE=/root/.local/share/fish/fish_history
+readonly FISH_HISTORY_PERSISTENT_FILE=/data/fish_history
 readonly GIT_CONFIG=/data/.gitconfig
 readonly HOME_ASSISTANT_PROFILE_D_FILE=/etc/profile.d/homeassistant.sh
 readonly SSH_USER_PATH=/data/.ssh
@@ -14,6 +18,104 @@ readonly VSCODE_SERVER_PATH=/root/.vscode-server
 readonly VSCODE_SERVER_PERSISTENT_PATH=/data/.vscode-server
 readonly ZSH_HISTORY_FILE=/root/.zsh_history
 readonly ZSH_HISTORY_PERSISTENT_FILE=/data/.zsh_history
+declare login_shell
+declare session_backend
+declare shell_path
+
+get_login_shell() {
+    if bashio::config.has_value 'shell'; then
+        bashio::config 'shell'
+    elif bashio::config.true 'zsh'; then
+        echo 'zsh'
+    else
+        echo 'bash'
+    fi
+}
+
+get_shell_path() {
+    case "$1" in
+        fish)
+            echo '/usr/bin/fish'
+            ;;
+        zsh)
+            echo '/bin/zsh'
+            ;;
+        bash)
+            echo '/bin/bash'
+            ;;
+        *)
+            bashio::exit.nok "Unsupported shell: $1"
+            ;;
+    esac
+}
+
+get_session_backend() {
+    if bashio::config.has_value 'session_backend'; then
+        bashio::config 'session_backend'
+    else
+        echo 'zellij'
+    fi
+}
+
+set_root_shell() {
+    sed -i -r -e "s|^(root:[^:]*:[^:]*:[^:]*:[^:]*:[^:]*:).*|\1$1|" /etc/passwd* \
+        || bashio::exit.nok 'Failed setting the root login shell'
+}
+
+write_bash_profile() {
+    cat > /root/.bash_profile <<EOF
+if [[ -z "\${TMUX}" ]] && [[ -z "\${ZELLIJ}" ]]; then
+  case "${session_backend}" in
+    zellij)
+      exec zellij attach --create homeassistant options --default-shell "${shell_path}"
+      ;;
+    tmux)
+      exec tmux -u new -A -s homeassistant "${shell_path}" -l
+      ;;
+  esac
+fi
+EOF
+}
+
+write_zsh_profile() {
+    cat > /root/.zprofile <<EOF
+if [[ -z "\${TMUX}" ]] && [[ -z "\${ZELLIJ}" ]] && [[ -o interactive ]]; then
+  case "${session_backend}" in
+    zellij)
+      exec zellij attach --create homeassistant options --default-shell "${shell_path}"
+      ;;
+    tmux)
+      exec tmux -u new -A -s homeassistant "${shell_path}" -l
+      ;;
+  esac
+fi
+EOF
+}
+
+write_fish_config() {
+    mkdir -p "${FISH_CONF_D_PATH}" /root/.local/share/fish \
+        || bashio::exit.nok 'Failed creating Fish configuration directories'
+
+    cat > "${FISH_HOME_ASSISTANT_CONF_D_FILE}" <<EOF
+set -gx SUPERVISOR_TOKEN "${SUPERVISOR_TOKEN}"
+EOF
+
+    if bashio::config.true 'share_sessions'; then
+        cat >> "${FISH_HOME_ASSISTANT_CONF_D_FILE}" <<EOF
+
+if status is-interactive
+    if test -z "\$TMUX"; and test -z "\$ZELLIJ"
+        switch "${session_backend}"
+            case zellij
+                exec zellij attach --create homeassistant options --default-shell "${shell_path}"
+            case tmux
+                exec tmux -u new -A -s homeassistant "${shell_path}" -l
+        end
+    end
+end
+EOF
+    fi
+}
 
 # Links some common directories to the user's home folder for convenience
 for dir in "${DIRECTORIES[@]}"; do
@@ -27,34 +129,57 @@ ln -s "/homeassistant" "/config" \
 ln -s "/homeassistant" "${HOME}/config" \
     || bashio::log.warning "Failed linking common directory: ${HOME}/config"
 
-# Sets up ZSH or Bash shell history
-if bashio::config.true "zsh"; then
-    touch "${ZSH_HISTORY_PERSISTENT_FILE}" \
-        || bashio::exit.nok 'Failed creating a persistent ZSH history file'
+login_shell=$(get_login_shell)
+shell_path=$(get_shell_path "${login_shell}")
+session_backend=$(get_session_backend)
 
-    chmod 600 "${ZSH_HISTORY_PERSISTENT_FILE}" \
-        || bashio::exit.nok \
-            'Failed setting the correct permissions to the ZSH history file'
+# Sets up shell history
+case "${login_shell}" in
+    fish)
+        mkdir -p /root/.local/share/fish \
+            || bashio::exit.nok 'Failed creating the Fish history directory'
 
-    ln -s -f "${ZSH_HISTORY_PERSISTENT_FILE}" "${ZSH_HISTORY_FILE}" \
-        || bashio::exit.nok 'Failed linking the persistent ZSH history file'
-else
-    touch "${BASH_HISTORY_PERSISTENT_FILE}" \
-        || bashio::exit.nok 'Failed creating a persistent Bash history file'
+        touch "${FISH_HISTORY_PERSISTENT_FILE}" \
+            || bashio::exit.nok 'Failed creating a persistent Fish history file'
 
-    chmod 600 "${BASH_HISTORY_PERSISTENT_FILE}" \
-        || bashio::exit.nok \
-            'Failed setting the correct permissions to the Bash history file'
+        chmod 600 "${FISH_HISTORY_PERSISTENT_FILE}" \
+            || bashio::exit.nok \
+                'Failed setting the correct permissions to the Fish history file'
 
-    ln -s -f "${BASH_HISTORY_PERSISTENT_FILE}" "${BASH_HISTORY_FILE}" \
-        || bashio::exit.nok 'Failed linking the persistent Bash history file'
-fi
+        ln -s -f "${FISH_HISTORY_PERSISTENT_FILE}" "${FISH_HISTORY_FILE}" \
+            || bashio::exit.nok 'Failed linking the persistent Fish history file'
+        ;;
+    zsh)
+        touch "${ZSH_HISTORY_PERSISTENT_FILE}" \
+            || bashio::exit.nok 'Failed creating a persistent ZSH history file'
 
-# Set up Bash
-if ! bashio::config.true "zsh"; then
-    sed -i -r -e 's|^(root:.*)/bin/zsh$|\1/bin/bash|' /etc/passwd*
-    sed -i -e 's|/zsh$|/bash|' /root/.tmux.conf
-fi
+        chmod 600 "${ZSH_HISTORY_PERSISTENT_FILE}" \
+            || bashio::exit.nok \
+                'Failed setting the correct permissions to the ZSH history file'
+
+        ln -s -f "${ZSH_HISTORY_PERSISTENT_FILE}" "${ZSH_HISTORY_FILE}" \
+            || bashio::exit.nok 'Failed linking the persistent ZSH history file'
+        ;;
+    bash)
+        touch "${BASH_HISTORY_PERSISTENT_FILE}" \
+            || bashio::exit.nok 'Failed creating a persistent Bash history file'
+
+        chmod 600 "${BASH_HISTORY_PERSISTENT_FILE}" \
+            || bashio::exit.nok \
+                'Failed setting the correct permissions to the Bash history file'
+
+        ln -s -f "${BASH_HISTORY_PERSISTENT_FILE}" "${BASH_HISTORY_FILE}" \
+            || bashio::exit.nok 'Failed linking the persistent Bash history file'
+        ;;
+esac
+
+# Configure the selected root login shell and tmux default shell.
+set_root_shell "${shell_path}"
+sed -i -r -e "s|^(set-option -g default-shell ).*|\1${shell_path}|" /root/.tmux.conf \
+    || bashio::exit.nok 'Failed configuring tmux default shell'
+
+# Configure Fish, including the Supervisor token for Fish login sessions.
+write_fish_config
 
 echo "export SUPERVISOR_TOKEN=\"${SUPERVISOR_TOKEN}\"" \
     >> "${HOME_ASSISTANT_PROFILE_D_FILE}" \
@@ -88,17 +213,20 @@ if ! bashio::fs.directory_exists "${VSCODE_SERVER_PERSISTENT_PATH}"; then
 fi
 ln -s "${VSCODE_SERVER_PERSISTENT_PATH}" "${VSCODE_SERVER_PATH}"
 
-# Disable SSH & Web Terminal session sharing if configured
-if ! bashio::config.true 'share_sessions'; then
+# Configure SSH & Web Terminal session sharing if requested.
+if bashio::config.true 'share_sessions'; then
+    write_bash_profile
+    write_zsh_profile
+else
     bashio::log.notice 'Session sharing has been disabled!'
-    rm /root/.bash_profile
-    rm /root/.zprofile
+    rm -f /root/.bash_profile
+    rm -f /root/.zprofile
 fi
 
 # Install user configured/requested packages
 #
 # Failures here are intentionally non-fatal: if the package indexes or a
-# package cannot be fetched (e.g. broken DNS or no network), we still want
+# package cannot be fetched (e.g., broken DNS or no network), we still want
 # the terminal to come up so the host remains reachable for debugging.
 if bashio::config.has_value 'packages'; then
     if apk update; then
@@ -119,11 +247,11 @@ if bashio::config.has_value 'init_commands'; then
     # Use bashio::config to properly iterate over the array, preserving multi-line commands
     length=$(bashio::config 'init_commands | length') \
         || bashio::exit.nok 'Failed to get init_commands array length'
-    
+
     for (( i=0; i<length; i++ )); do
         cmd=$(bashio::config "init_commands[${i}]") \
             || bashio::exit.nok "Failed to get init command at index ${i}"
-        
+
         eval "${cmd}" \
             || bashio::exit.nok "Failed executing init command: ${cmd}"
     done
diff --git a/ssh/rootfs/etc/s6-overlay/s6-rc.d/ttyd/run b/ssh/rootfs/etc/s6-overlay/s6-rc.d/ttyd/run
index abd96cb4..4b3b42e2 100755
--- a/ssh/rootfs/etc/s6-overlay/s6-rc.d/ttyd/run
+++ b/ssh/rootfs/etc/s6-overlay/s6-rc.d/ttyd/run
@@ -7,6 +7,44 @@
 declare ttyd_command
 declare -a options
 declare ingress_port
+declare login_shell
+declare session_backend
+declare shell_path
+
+get_login_shell() {
+    if bashio::config.has_value 'shell'; then
+        bashio::config 'shell'
+    elif bashio::config.true 'zsh'; then
+        echo 'zsh'
+    else
+        echo 'bash'
+    fi
+}
+
+get_shell_path() {
+    case "$1" in
+        fish)
+            echo '/usr/bin/fish'
+            ;;
+        zsh)
+            echo '/bin/zsh'
+            ;;
+        bash)
+            echo '/bin/bash'
+            ;;
+        *)
+            bashio::exit.nok "Unsupported shell: $1"
+            ;;
+    esac
+}
+
+get_session_backend() {
+    if bashio::config.has_value 'session_backend'; then
+        bashio::config 'session_backend'
+    else
+        echo 'zellij'
+    fi
+}
 
 bashio::log.info 'Starting the ttyd daemon...'
 
@@ -27,10 +65,21 @@ options+=(--writable)
 ingress_port=$(bashio::app.ingress_port)
 options+=(-p "${ingress_port}")
 
-ttyd_command=(tmux -u new -A -s homeassistant zsh -l)
-if ! bashio::config.true "zsh"; then
-    ttyd_command=(tmux -u new -A -s homeassistant bash -l)
-fi
+login_shell=$(get_login_shell)
+shell_path=$(get_shell_path "${login_shell}")
+session_backend=$(get_session_backend)
+
+case "${session_backend}" in
+    zellij)
+        ttyd_command=(zellij attach --create homeassistant options --default-shell "${shell_path}")
+        ;;
+    tmux)
+        ttyd_command=(tmux -u new -A -s homeassistant "${shell_path}" -l)
+        ;;
+    *)
+        bashio::exit.nok "Unsupported session backend: ${session_backend}"
+        ;;
+esac
 
 # Change working directory
 cd /root || bashio::exit.nok 'Unable to change working directory'