diff --git a/share/functions/fish_vi_key_bindings.fish b/share/functions/fish_vi_key_bindings.fish
index ddfaf6e86..f83bfe0a3 100644
--- a/share/functions/fish_vi_key_bindings.fish
+++ b/share/functions/fish_vi_key_bindings.fish
@@ -187,7 +187,7 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
     bind -s --preset -m insert ci backward-jump-till and repeat-jump-reverse and begin-selection repeat-jump kill-selection end-selection repaint-mode
     bind -s --preset -m insert ca backward-jump and repeat-jump-reverse and begin-selection repeat-jump kill-selection end-selection repaint-mode
 
-    bind -s --preset '~' capitalize-word
+    bind -s --preset '~' togglecase-char forward-char
     bind -s --preset gu downcase-word
     bind -s --preset gU upcase-word
 
@@ -291,6 +291,7 @@ function fish_vi_key_bindings --description 'vi-like key bindings for fish'
     bind -s --preset -M visual -m default X kill-whole-line end-selection repaint-mode
     bind -s --preset -M visual -m default y kill-selection yank end-selection repaint-mode
     bind -s --preset -M visual -m default '"*y' "commandline -s | xsel -p; commandline -f end-selection repaint-mode"
+    bind -s --preset -M visual -m default '~' togglecase-selection end-selection repaint-mode
 
     bind -s --preset -M visual -m default \cc end-selection repaint-mode
     bind -s --preset -M visual -m default \e end-selection repaint-mode
diff --git a/src/input.cpp b/src/input.cpp
index 72f84a509..0c53d77ca 100644
--- a/src/input.cpp
+++ b/src/input.cpp
@@ -123,6 +123,8 @@ static const input_function_metadata_t input_function_metadata[] = {
     {readline_cmd_t::upcase_word, L"upcase-word"},
     {readline_cmd_t::downcase_word, L"downcase-word"},
     {readline_cmd_t::capitalize_word, L"capitalize-word"},
+    {readline_cmd_t::togglecase_char, L"togglecase-char"},
+    {readline_cmd_t::togglecase_selection, L"togglecase-selection"},
     {readline_cmd_t::execute, L"execute"},
     {readline_cmd_t::beginning_of_buffer, L"beginning-of-buffer"},
     {readline_cmd_t::end_of_buffer, L"end-of-buffer"},
diff --git a/src/input_common.h b/src/input_common.h
index 746b4f6d6..901acf678 100644
--- a/src/input_common.h
+++ b/src/input_common.h
@@ -48,6 +48,8 @@ enum class readline_cmd_t {
     upcase_word,
     downcase_word,
     capitalize_word,
+    togglecase_char,
+    togglecase_selection,
     execute,
     beginning_of_buffer,
     end_of_buffer,
diff --git a/src/reader.cpp b/src/reader.cpp
index f607cbff4..ce2a0bc3a 100644
--- a/src/reader.cpp
+++ b/src/reader.cpp
@@ -3219,6 +3219,72 @@ void reader_data_t::handle_readline_command(readline_cmd_t c, readline_loop_stat
             }
             break;
         }
+        case rl::togglecase_char: {
+            editable_line_t *el = active_edit_line();
+            size_t buff_pos = el->position();
+
+            // Check that the cursor is on a character
+            if (buff_pos < el->size()) {
+                wchar_t chr = el->text().at(buff_pos);
+                wcstring replacement;
+
+                // Toggle the case of the current character
+                bool make_uppercase = iswlower(chr);
+                if (make_uppercase) {
+                    chr = towupper(chr);
+                } else {
+                    chr = tolower(chr);
+                }
+
+                replacement.push_back(chr);
+                el->replace_substring(buff_pos, (size_t)1, std::move(replacement));
+
+                // Restore the buffer position since replace_substring moves
+                // the buffer position ahead of the replaced text.
+                update_buff_pos(el, buff_pos);
+
+                command_line_changed(el);
+                super_highlight_me_plenty();
+                reader_repaint_needed();
+            }
+            break;
+        }
+        case rl::togglecase_selection: {
+            editable_line_t *el = active_edit_line();
+
+            // Check that we have an active selection and get the bounds.
+            size_t start, len;
+            if (reader_get_selection(&start, &len)) {
+                size_t buff_pos = el->position();
+                wcstring replacement;
+
+                // Loop through the selected characters and toggle their case.
+                for (size_t pos = start; pos < start + len && pos < el->size(); pos++) {
+                    wchar_t chr = el->text().at(pos);
+
+                    // Toggle the case of the current character.
+                    bool make_uppercase = iswlower(chr);
+                    if (make_uppercase) {
+                        chr = towupper(chr);
+                    } else {
+                        chr = tolower(chr);
+                    }
+
+                    replacement.push_back(chr);
+                }
+
+                el->replace_substring(start, len, std::move(replacement));
+
+                // Restore the buffer position since replace_substring moves
+                // the buffer position ahead of the replaced text.
+                update_buff_pos(el, buff_pos);
+
+                command_line_changed(el);
+                super_highlight_me_plenty();
+                reader_repaint_needed();
+            }
+            break;
+        }
         case rl::upcase_word:
         case rl::downcase_word:
         case rl::capitalize_word: {