diff --git a/Library/Homebrew/cmd/leaves.rb b/Library/Homebrew/cmd/leaves.rb
index 76fb8784ca..72241fb95d 100644
--- a/Library/Homebrew/cmd/leaves.rb
+++ b/Library/Homebrew/cmd/leaves.rb
@@ -11,7 +11,7 @@ module Homebrew
   def leaves_args
     Homebrew::CLI::Parser.new do
       description <<~EOS
-        List installed formulae that are not dependencies of another installed formula.
+        List installed formulae that are not dependencies of another installed formula and cask.
       EOS
       switch "-r", "--installed-on-request",
              description: "Only list leaves that were manually installed."
@@ -36,7 +36,10 @@ module Homebrew
     args = leaves_args.parse
 
     leaves_list = Formula.installed - Formula.installed.flat_map(&:runtime_formula_dependencies)
-
+    casks_runtime_dependencies = Cask::Caskroom.casks.flat_map do |cask|
+      CaskDependent.new(cask).runtime_dependencies.map(&:to_formula)
+    end
+    leaves_list -= casks_runtime_dependencies
     leaves_list.select!(&method(:installed_on_request?)) if args.installed_on_request?
     leaves_list.select!(&method(:installed_as_dependency?)) if args.installed_as_dependency?