diff --git a/ansible/dotfiles.yml b/ansible/dotfiles.yml
index 3270da9..9f1ba78 100644
--- a/ansible/dotfiles.yml
+++ b/ansible/dotfiles.yml
@@ -52,6 +52,12 @@
       tags:
         - agents
 
+    - name: Include tmux setup tasks
+      include_tasks: tasks/tmux.yml
+      tags:
+        - tmux
+        - setup
+
     - name: Include dotfile linking tasks
       include_tasks: tasks/link_files.yml
       tags:
diff --git a/ansible/tasks/link_files.yml b/ansible/tasks/link_files.yml
index f02572c..ccd0960 100644
--- a/ansible/tasks/link_files.yml
+++ b/ansible/tasks/link_files.yml
@@ -40,6 +40,7 @@
     - { src: "github/create_pr.bash", dest: ".bin/pr" }
     - { src: "hammerspoon/init.lua", dest: ".hammerspoon/init.lua" }
     - { src: "ghostty/config", dest: ".config/ghostty/config" }
+    - { src: "tmux/tmux.conf", dest: ".tmux.conf" }
     - {
         src: "python/scratch_python_project.sh",
         dest: ".bin/scratch_python_project",
diff --git a/ansible/tasks/tmux.yml b/ansible/tasks/tmux.yml
new file mode 100644
index 0000000..d40f8b0
--- /dev/null
+++ b/ansible/tasks/tmux.yml
@@ -0,0 +1,12 @@
+---
+- name: Clone TPM (Tmux Plugin Manager)
+  ansible.builtin.git:
+    repo: https://github.com/tmux-plugins/tpm
+    dest: "{{ ansible_user_dir }}/.tmux/plugins/tpm"
+    depth: 1
+
+- name: Install tmux plugins via TPM
+  ansible.builtin.command:
+    cmd: "{{ ansible_user_dir }}/.tmux/plugins/tpm/bin/install_plugins"
+  environment:
+    TMUX_PLUGIN_MANAGER_PATH: "{{ ansible_user_dir }}/.tmux/plugins"
diff --git a/fish/config.fish b/fish/config.fish
index e30e007..b24e78e 100644
--- a/fish/config.fish
+++ b/fish/config.fish
@@ -20,6 +20,11 @@ if test "$TERM_PROGRAM" = vscode
     exit 0
 end
 
+# Auto-attach to tmux in Ghostty (but not inside nvim, scripts, or existing tmux)
+if test "$TERM_PROGRAM" = ghostty; and not set -q TMUX; and not set -q NVIM; and status is-interactive
+    tmux new-session -A -s main
+end
+
 # Initialize starship and zoxide
 starship init fish | source
 zoxide init fish | source
diff --git a/ghostty/config b/ghostty/config
index 47b98bb..e0a9a88 100644
--- a/ghostty/config
+++ b/ghostty/config
@@ -4,3 +4,7 @@ font-size = 16
 shell-integration = fish
 theme = Catppuccin Frappe
 command = /opt/homebrew/bin/fish
+
+# Let tmux handle all window/tab management
+keybind = super+t=unbind
+keybind = super+n=unbind
diff --git a/nvim/lua/plugins/tmux-navigator.lua b/nvim/lua/plugins/tmux-navigator.lua
new file mode 100644
index 0000000..688b62e
--- /dev/null
+++ b/nvim/lua/plugins/tmux-navigator.lua
@@ -0,0 +1,16 @@
+return {
+  "christoomey/vim-tmux-navigator",
+  cmd = {
+    "TmuxNavigateLeft",
+    "TmuxNavigateDown",
+    "TmuxNavigateUp",
+    "TmuxNavigateRight",
+    "TmuxNavigatePrevious",
+  },
+  keys = {
+    { "<C-h>", "<cmd>TmuxNavigateLeft<cr>", desc = "Navigate left" },
+    { "<C-j>", "<cmd>TmuxNavigateDown<cr>", desc = "Navigate down" },
+    { "<C-k>", "<cmd>TmuxNavigateUp<cr>", desc = "Navigate up" },
+    { "<C-l>", "<cmd>TmuxNavigateRight<cr>", desc = "Navigate right" },
+  },
+}
diff --git a/nvim/lua/plugins/toggleterm.lua b/nvim/lua/plugins/toggleterm.lua
index 0cd8803..455160b 100644
--- a/nvim/lua/plugins/toggleterm.lua
+++ b/nvim/lua/plugins/toggleterm.lua
@@ -78,10 +78,10 @@ return {
       local opts = { buffer = 0 }
       vim.keymap.set("t", "<esc>", [[<C-\><C-n>]], opts)
       vim.keymap.set("t", "jk", [[<C-\><C-n>]], opts)
-      vim.keymap.set("t", "<C-h>", [[<Cmd>wincmd h<CR>]], opts)
-      vim.keymap.set("t", "<C-j>", [[<Cmd>wincmd j<CR>]], opts)
-      vim.keymap.set("t", "<C-k>", [[<Cmd>wincmd k<CR>]], opts)
-      vim.keymap.set("t", "<C-l>", [[<Cmd>wincmd l<CR>]], opts)
+      vim.keymap.set("t", "<C-h>", [[<Cmd>TmuxNavigateLeft<CR>]], opts)
+      vim.keymap.set("t", "<C-j>", [[<Cmd>TmuxNavigateDown<CR>]], opts)
+      vim.keymap.set("t", "<C-k>", [[<Cmd>TmuxNavigateUp<CR>]], opts)
+      vim.keymap.set("t", "<C-l>", [[<Cmd>TmuxNavigateRight<CR>]], opts)
       vim.keymap.set("t", "<C-w>", [[<C-\><C-n><C-w>]], opts)
     end
 
diff --git a/tmux/cheatsheet.md b/tmux/cheatsheet.md
new file mode 100644
index 0000000..5d8b30c
--- /dev/null
+++ b/tmux/cheatsheet.md
@@ -0,0 +1,57 @@
+# Ghostty + tmux Cheatsheet
+
+Prefix key: `Ctrl-a`
+
+All window and tab management is handled by tmux. Ghostty's `Cmd-T` and
+`Cmd-N` are unbound to avoid conflicts.
+
+## tmux (prefix = Ctrl-a)
+
+### Sessions
+
+| Keys | Action |
+| --- | --- |
+| `prefix d` | Detach from session |
+| `prefix s` | List / switch sessions |
+| `prefix $` | Rename session |
+| `tmux new -s name` | New named session |
+
+### Windows (tabs inside tmux)
+
+| Keys | Action |
+| --- | --- |
+| `prefix c` | New window |
+| `prefix ,` | Rename window |
+| `prefix n` / `prefix p` | Next / previous window |
+| `prefix 1-9` | Jump to window by number |
+| `prefix Ctrl-a` | Toggle last window |
+| `prefix &` | Kill window |
+
+### Panes (splits inside a window)
+
+| Keys | Action |
+| --- | --- |
+| `prefix i` | Split horizontal |
+| `prefix u` | Split vertical |
+| `Ctrl-h/j/k/l` | Navigate panes (vim-tmux-navigator) |
+| `prefix z` | Zoom / unzoom pane |
+| `prefix x` | Kill pane |
+| `prefix Space` | Enter copy mode (vi keys) |
+
+### Copy mode (vi)
+
+| Keys | Action |
+| --- | --- |
+| `/` | Search forward |
+| `?` | Search backward |
+| `v` | Begin selection |
+| `y` | Yank selection |
+| `q` | Exit copy mode |
+
+## Ghostty
+
+| Keys | Action |
+| --- | --- |
+| `Cmd-+` / `Cmd--` | Zoom in / out |
+| `Cmd-Shift-,` | Open config |
+| `Cmd-K` | Clear screen |
diff --git a/tmux/tmux.conf b/tmux/tmux.conf
new file mode 100644
index 0000000..f6fafdd
--- /dev/null
+++ b/tmux/tmux.conf
@@ -0,0 +1,67 @@
+#{{{1 GENERAL OPTIONS
+
+set-option -g default-shell "/opt/homebrew/bin/fish"
+set-option -g default-terminal "tmux-256color"
+set-option -ga terminal-overrides ",xterm-ghostty:Tc"
+set-option -g history-limit 100000
+set-option -g focus-events on
+set-option -g escape-time 0
+set-option -g mouse on
+
+#{{{1 KEY BINDS
+
+#{{{2 UNBINDS
+
+unbind C-b
+unbind l
+unbind h
+unbind k
+unbind j
+unbind u
+unbind i
+unbind Space
+
+#{{{2 GENERAL
+
+set -g prefix C-a
+bind-key a send-prefix
+bind r source-file ~/.tmux.conf \; display-message "Config reloaded..."
+bind Space copy-mode
+set-window-option -g mode-keys vi
+
+#{{{2 WINDOWS
+
+bind-key C-a last-window
+
+#{{{2 PANES
+
+# Splits
+bind u split-window -v -c "#{pane_current_path}"
+bind i split-window -h -c "#{pane_current_path}"
+
+# Vim-tmux-navigator handles C-h/j/k/l pane switching
+# See: https://github.com/christoomey/vim-tmux-navigator
+
+#{{{1 WINDOW SETTINGS
+
+set -g base-index 1
+set-window-option -g pane-base-index 1
+set -g renumber-windows on
+set-window-option -g automatic-rename on
+set-option -g allow-rename off
+set -g set-titles on
+
+#{{{1 PLUGINS (TPM)
+
+set -g @plugin 'tmux-plugins/tpm'
+set -g @plugin 'christoomey/vim-tmux-navigator'
+set -g @plugin 'catppuccin/tmux'
+
+#{{{2 CATPPUCCIN
+
+set -g @catppuccin_flavor 'frappe'
+
+#{{{1 INITIALIZE TPM
+# (keep this line at the very bottom of tmux.conf)
+
+run '~/.tmux/plugins/tpm/tpm'