diff --git a/CHANGELOG.md b/CHANGELOG.md
index 05e7445..d571541 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,6 @@
 ## [Unreleased]
 
+- `git pkgs where` command to find where a package is declared in manifest files
 - `git pkgs diff-driver` command for semantic lockfile diffs in `git diff`
 
 ## [0.3.0] - 2026-01-03
diff --git a/README.md b/README.md
index 08f96e4..5c1c116 100644
--- a/README.md
+++ b/README.md
@@ -258,6 +258,23 @@ git pkgs show HEAD~5       # relative ref
 
 Like `git show` but for dependencies. Shows what was added, modified, or removed in a single commit.
 
+### Find where a package is declared
+
+```bash
+git pkgs where rails           # find in manifest files
+git pkgs where lodash -C 2     # show 2 lines of context
+git pkgs where express --ecosystem=npm
+```
+
+Shows which manifest files declare a package and the exact line:
+
+```
+Gemfile:5:gem "rails", "~> 7.0"
+Gemfile.lock:142:    rails (7.0.8)
+```
+
+Like `grep` but scoped to manifest files that git-pkgs knows about.
+
 ### List commits with dependency changes
 
 ```bash
diff --git a/lib/git/pkgs.rb b/lib/git/pkgs.rb
index 06b3e32..459fc3a 100644
--- a/lib/git/pkgs.rb
+++ b/lib/git/pkgs.rb
@@ -30,6 +30,7 @@
 require_relative "pkgs/commands/branch"
 require_relative "pkgs/commands/search"
 require_relative "pkgs/commands/show"
+require_relative "pkgs/commands/where"
 require_relative "pkgs/commands/log"
 require_relative "pkgs/commands/upgrade"
 require_relative "pkgs/commands/schema"
diff --git a/lib/git/pkgs/cli.rb b/lib/git/pkgs/cli.rb
index f0d09aa..7aa4c17 100644
--- a/lib/git/pkgs/cli.rb
+++ b/lib/git/pkgs/cli.rb
@@ -5,7 +5,7 @@
 module Git
   module Pkgs
     class CLI
-      COMMANDS = %w[init update hooks info list tree history search why blame stale stats diff branch show log upgrade schema diff-driver].freeze
+      COMMANDS = %w[init update hooks info list tree history search where why blame stale stats diff branch show log upgrade schema diff-driver].freeze
       ALIASES = { "praise" => "blame", "outdated" => "stale" }.freeze
 
       def self.run(args)
@@ -59,6 +59,7 @@ def print_help
             tree      Show dependency tree grouped by type
             history   Show the history of a package
             search    Find a dependency across all history
+            where     Show where a package appears in manifest files
             why       Explain why a dependency exists
             blame     Show who added each dependency
             stale     Show dependencies that haven't been updated
diff --git a/lib/git/pkgs/color.rb b/lib/git/pkgs/color.rb
index 2a04f60..45c0d84 100644
--- a/lib/git/pkgs/color.rb
+++ b/lib/git/pkgs/color.rb
@@ -74,6 +74,7 @@ def self.red(text)     = colorize(text, :red)
       def self.green(text)   = colorize(text, :green)
       def self.yellow(text)  = colorize(text, :yellow)
       def self.blue(text)    = colorize(text, :blue)
+      def self.magenta(text) = colorize(text, :magenta)
       def self.cyan(text)    = colorize(text, :cyan)
       def self.bold(text)    = colorize(text, :bold)
       def self.dim(text)     = colorize(text, :dim)
diff --git a/lib/git/pkgs/commands/where.rb b/lib/git/pkgs/commands/where.rb
new file mode 100644
index 0000000..572f5bd
--- /dev/null
+++ b/lib/git/pkgs/commands/where.rb
@@ -0,0 +1,166 @@
+# frozen_string_literal: true
+
+module Git
+  module Pkgs
+    module Commands
+      class Where
+        include Output
+
+        def initialize(args)
+          @args = args
+          @options = parse_options
+        end
+
+        def run
+          name = @args.first
+
+          error "Usage: git pkgs where <package-name>" unless name
+
+          repo = Repository.new
+          require_database(repo)
+
+          Database.connect(repo.git_dir)
+
+          workdir = File.dirname(repo.git_dir)
+          branch = Models::Branch.find_by(name: @options[:branch] || repo.default_branch)
+
+          unless branch
+            error "Branch not found. Run 'git pkgs init' first."
+          end
+
+          snapshots = Models::DependencySnapshot.current_for_branch(branch)
+          snapshots = snapshots.where(ecosystem: @options[:ecosystem]) if @options[:ecosystem]
+
+          manifest_paths = snapshots.for_package(name).joins(:manifest).pluck("manifests.path").uniq
+
+          if manifest_paths.empty?
+            empty_result "Package '#{name}' not found in current dependencies"
+            return
+          end
+
+          results = manifest_paths.flat_map do |path|
+            find_in_manifest(name, File.join(workdir, path), path)
+          end
+
+          if results.empty?
+            empty_result "Package '#{name}' tracked but not found in current files"
+            return
+          end
+
+          if @options[:format] == "json"
+            output_json(results)
+          else
+            paginate { output_text(results, name) }
+          end
+        end
+
+        def find_in_manifest(name, full_path, display_path)
+          return [] unless File.exist?(full_path)
+
+          lines = File.readlines(full_path)
+          matches = []
+
+          lines.each_with_index do |line, idx|
+            next unless line.include?(name)
+
+            match = { path: display_path, line: idx + 1, content: line.rstrip }
+
+            if context_lines > 0
+              match[:before] = context_before(lines, idx)
+              match[:after] = context_after(lines, idx)
+            end
+
+            matches << match
+          end
+
+          matches
+        end
+
+        def context_lines
+          @options[:context] || 0
+        end
+
+        def context_before(lines, idx)
+          start_idx = [0, idx - context_lines].max
+          (start_idx...idx).map { |i| { line: i + 1, content: lines[i].rstrip } }
+        end
+
+        def context_after(lines, idx)
+          end_idx = [lines.length - 1, idx + context_lines].min
+          ((idx + 1)..end_idx).map { |i| { line: i + 1, content: lines[i].rstrip } }
+        end
+
+        def output_text(results, name)
+          results.each_with_index do |result, i|
+            puts "--" if i > 0 && context_lines > 0
+
+            result[:before]&.each do |ctx|
+              puts format_context_line(result[:path], ctx[:line], ctx[:content])
+            end
+
+            puts format_match_line(result[:path], result[:line], result[:content], name)
+
+            result[:after]&.each do |ctx|
+              puts format_context_line(result[:path], ctx[:line], ctx[:content])
+            end
+          end
+        end
+
+        def format_match_line(path, line_num, content, name)
+          path_str = Color.magenta(path)
+          line_str = Color.green(line_num.to_s)
+          highlighted = content.gsub(name, Color.red(name))
+          "#{path_str}:#{line_str}:#{highlighted}"
+        end
+
+        def format_context_line(path, line_num, content)
+          path_str = Color.magenta(path)
+          line_str = Color.green(line_num.to_s)
+          content_str = Color.dim(content)
+          "#{path_str}-#{line_str}-#{content_str}"
+        end
+
+        def output_json(results)
+          require "json"
+          puts JSON.pretty_generate(results)
+        end
+
+        def parse_options
+          options = {}
+
+          parser = OptionParser.new do |opts|
+            opts.banner = "Usage: git pkgs where <package-name> [options]"
+
+            opts.on("-b", "--branch=NAME", "Branch to search (default: current)") do |v|
+              options[:branch] = v
+            end
+
+            opts.on("-e", "--ecosystem=NAME", "Filter by ecosystem") do |v|
+              options[:ecosystem] = v
+            end
+
+            opts.on("-C", "--context=NUM", Integer, "Show NUM lines of context") do |v|
+              options[:context] = v
+            end
+
+            opts.on("-f", "--format=FORMAT", "Output format (text, json)") do |v|
+              options[:format] = v
+            end
+
+            opts.on("--no-pager", "Do not pipe output into a pager") do
+              options[:no_pager] = true
+            end
+
+            opts.on("-h", "--help", "Show this help") do
+              puts opts
+              exit
+            end
+          end
+
+          parser.parse!(@args)
+          options
+        end
+      end
+    end
+  end
+end
diff --git a/test/git/pkgs/test_cli.rb b/test/git/pkgs/test_cli.rb
index 1bf8faf..87bf2b8 100644
--- a/test/git/pkgs/test_cli.rb
+++ b/test/git/pkgs/test_cli.rb
@@ -833,6 +833,106 @@ def capture_stdout
   end
 end
 
+class Git::Pkgs::TestWhereCommand < Minitest::Test
+  include TestHelpers
+
+  def setup
+    create_test_repo
+    add_file("Gemfile", sample_gemfile({ "rails" => "~> 7.0", "puma" => "~> 5.0" }))
+    commit("Add dependencies")
+    @git_dir = File.join(@test_dir, ".git")
+    Git::Pkgs::Database.connect(@git_dir)
+    Git::Pkgs::Database.create_schema
+
+    # Create branch and snapshot
+    repo = Git::Pkgs::Repository.new(@test_dir)
+    Git::Pkgs::Models::Branch.create!(name: repo.default_branch, last_analyzed_sha: repo.head_sha)
+    rugged_commit = repo.lookup(repo.head_sha)
+    commit_record = Git::Pkgs::Models::Commit.find_or_create_from_rugged(rugged_commit)
+
+    manifest = Git::Pkgs::Models::Manifest.create!(
+      path: "Gemfile",
+      ecosystem: "rubygems",
+      kind: "manifest"
+    )
+
+    Git::Pkgs::Models::DependencySnapshot.create!(
+      commit: commit_record,
+      manifest: manifest,
+      name: "rails",
+      ecosystem: "rubygems",
+      requirement: "~> 7.0"
+    )
+
+    Git::Pkgs::Models::DependencySnapshot.create!(
+      commit: commit_record,
+      manifest: manifest,
+      name: "puma",
+      ecosystem: "rubygems",
+      requirement: "~> 5.0"
+    )
+  end
+
+  def teardown
+    cleanup_test_repo
+  end
+
+  def test_where_finds_package_in_manifest
+    output = capture_stdout do
+      Dir.chdir(@test_dir) do
+        Git::Pkgs::Commands::Where.new(["rails"]).run
+      end
+    end
+
+    assert_includes output, "Gemfile"
+    assert_includes output, "rails"
+  end
+
+  def test_where_shows_line_number
+    output = capture_stdout do
+      Dir.chdir(@test_dir) do
+        Git::Pkgs::Commands::Where.new(["rails"]).run
+      end
+    end
+
+    # Output format: path:line:content
+    assert_match(/Gemfile:\d+:.*rails/, output)
+  end
+
+  def test_where_not_found
+    output = capture_stdout do
+      Dir.chdir(@test_dir) do
+        Git::Pkgs::Commands::Where.new(["nonexistent"]).run
+      end
+    end
+
+    assert_includes output, "not found"
+  end
+
+  def test_where_json_format
+    output = capture_stdout do
+      Dir.chdir(@test_dir) do
+        Git::Pkgs::Commands::Where.new(["rails", "--format=json"]).run
+      end
+    end
+
+    data = JSON.parse(output)
+    assert_equal 1, data.length
+    assert_equal "Gemfile", data.first["path"]
+    assert data.first["line"].is_a?(Integer)
+    assert_includes data.first["content"], "rails"
+  end
+
+  def capture_stdout
+    original = $stdout
+    $stdout = StringIO.new
+    yield
+    $stdout.string
+  ensure
+    $stdout = original
+  end
+end
+
 class Git::Pkgs::TestSchemaCommand < Minitest::Test
   include TestHelpers