diff --git a/devtools/client/shared/widgets/SimpleListWidget.jsm b/devtools/client/shared/widgets/SimpleListWidget.jsm
deleted file mode 100644
index af61b632cc58..000000000000
--- a/devtools/client/shared/widgets/SimpleListWidget.jsm
+++ /dev/null
@@ -1,251 +0,0 @@
-/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-"use strict";
-
-const { require } = ChromeUtils.import("resource://devtools/shared/Loader.jsm");
-const { ViewHelpers } = require("devtools/client/shared/widgets/view-helpers");
-
-this.EXPORTED_SYMBOLS = ["SimpleListWidget"];
-
-/**
- * A very simple vertical list view.
- *
- * Note: this widget should be used in tandem with the WidgetMethods in
- * view-helpers.js.
- *
- * @param Node aNode
- *        The element associated with the widget.
- */
-function SimpleListWidget(aNode) {
-  this.document = aNode.ownerDocument;
-  this.window = this.document.defaultView;
-  this._parent = aNode;
-
-  // Create an internal list container.
-  this._list = this.document.createElement("scrollbox");
-  this._list.className = "simple-list-widget-container theme-body";
-  this._list.setAttribute("flex", "1");
-  this._list.setAttribute("orient", "vertical");
-  this._parent.appendChild(this._list);
-
-  // Delegate some of the associated node's methods to satisfy the interface
-  // required by WidgetMethods instances.
-  ViewHelpers.delegateWidgetAttributeMethods(this, aNode);
-  ViewHelpers.delegateWidgetEventMethods(this, aNode);
-}
-this.SimpleListWidget = SimpleListWidget;
-
-SimpleListWidget.prototype = {
-  /**
-   * Inserts an item in this container at the specified index.
-   *
-   * @param number aIndex
-   *        The position in the container intended for this item.
-   * @param Node aContents
-   *        The node displayed in the container.
-   * @return Node
-   *         The element associated with the displayed item.
-   */
-  insertItemAt: function(aIndex, aContents) {
-    aContents.classList.add("simple-list-widget-item");
-
-    const list = this._list;
-    return list.insertBefore(aContents, list.childNodes[aIndex]);
-  },
-
-  /**
-   * Returns the child node in this container situated at the specified index.
-   *
-   * @param number aIndex
-   *        The position in the container intended for this item.
-   * @return Node
-   *         The element associated with the displayed item.
-   */
-  getItemAtIndex: function(aIndex) {
-    return this._list.childNodes[aIndex];
-  },
-
-  /**
-   * Immediately removes the specified child node from this container.
-   *
-   * @param Node aChild
-   *        The element associated with the displayed item.
-   */
-  removeChild: function(aChild) {
-    this._list.removeChild(aChild);
-
-    if (this._selectedItem == aChild) {
-      this._selectedItem = null;
-    }
-  },
-
-  /**
-   * Removes all of the child nodes from this container.
-   */
-  removeAllItems: function() {
-    const list = this._list;
-    const parent = this._parent;
-
-    while (list.hasChildNodes()) {
-      list.firstChild.remove();
-    }
-
-    parent.scrollTop = 0;
-    parent.scrollLeft = 0;
-    this._selectedItem = null;
-  },
-
-  /**
-   * Gets the currently selected child node in this container.
-   * @return Node
-   */
-  get selectedItem() {
-    return this._selectedItem;
-  },
-
-  /**
-   * Sets the currently selected child node in this container.
-   * @param Node aChild
-   */
-  set selectedItem(aChild) {
-    const childNodes = this._list.childNodes;
-
-    if (!aChild) {
-      this._selectedItem = null;
-    }
-    for (const node of childNodes) {
-      if (node == aChild) {
-        node.classList.add("selected");
-        this._selectedItem = node;
-      } else {
-        node.classList.remove("selected");
-      }
-    }
-  },
-
-  /**
-   * Adds a new attribute or changes an existing attribute on this container.
-   *
-   * @param string aName
-   *        The name of the attribute.
-   * @param string aValue
-   *        The desired attribute value.
-   */
-  setAttribute: function(aName, aValue) {
-    this._parent.setAttribute(aName, aValue);
-
-    if (aName == "emptyText") {
-      this._textWhenEmpty = aValue;
-    } else if (aName == "headerText") {
-      this._textAsHeader = aValue;
-    }
-  },
-
-  /**
-   * Removes an attribute on this container.
-   *
-   * @param string aName
-   *        The name of the attribute.
-   */
-  removeAttribute: function(aName) {
-    this._parent.removeAttribute(aName);
-
-    if (aName == "emptyText") {
-      this._removeEmptyText();
-    }
-  },
-
-  /**
-   * Ensures the specified element is visible.
-   *
-   * @param Node aElement
-   *        The element to make visible.
-   */
-  ensureElementIsVisible: function(aElement) {
-    if (!aElement) {
-      return;
-    }
-
-    // Ensure the element is visible but not scrolled horizontally.
-    aElement.scrollIntoView({ block: "nearest" });
-    this._list.scrollBy(-this._list.clientWidth, 0);
-  },
-
-  /**
-   * Sets the text displayed permanently in this container as a header.
-   * @param string aValue
-   */
-  set _textAsHeader(aValue) {
-    if (this._headerTextNode) {
-      this._headerTextNode.setAttribute("value", aValue);
-    }
-    this._headerTextValue = aValue;
-    this._showHeaderText();
-  },
-
-  /**
-   * Sets the text displayed in this container when empty.
-   * @param string aValue
-   */
-  set _textWhenEmpty(aValue) {
-    if (this._emptyTextNode) {
-      this._emptyTextNode.setAttribute("value", aValue);
-    }
-    this._emptyTextValue = aValue;
-    this._showEmptyText();
-  },
-
-  /**
-   * Creates and appends a label displayed as this container's header.
-   */
-  _showHeaderText: function() {
-    if (this._headerTextNode || !this._headerTextValue) {
-      return;
-    }
-    const label = this.document.createElement("label");
-    label.className = "plain simple-list-widget-perma-text";
-    label.setAttribute("value", this._headerTextValue);
-
-    this._parent.insertBefore(label, this._list);
-    this._headerTextNode = label;
-  },
-
-  /**
-   * Creates and appends a label signaling that this container is empty.
-   */
-  _showEmptyText: function() {
-    if (this._emptyTextNode || !this._emptyTextValue) {
-      return;
-    }
-    const label = this.document.createElement("label");
-    label.className = "plain simple-list-widget-empty-text";
-    label.setAttribute("value", this._emptyTextValue);
-
-    this._parent.appendChild(label);
-    this._emptyTextNode = label;
-  },
-
-  /**
-   * Removes the label signaling that this container is empty.
-   */
-  _removeEmptyText: function() {
-    if (!this._emptyTextNode) {
-      return;
-    }
-    this._parent.removeChild(this._emptyTextNode);
-    this._emptyTextNode = null;
-  },
-
-  window: null,
-  document: null,
-  _parent: null,
-  _list: null,
-  _selectedItem: null,
-  _headerTextNode: null,
-  _headerTextValue: "",
-  _emptyTextNode: null,
-  _emptyTextValue: "",
-};
diff --git a/devtools/client/shared/widgets/moz.build b/devtools/client/shared/widgets/moz.build
index 70b094a1b9e2..1eea16b37f0f 100644
--- a/devtools/client/shared/widgets/moz.build
+++ b/devtools/client/shared/widgets/moz.build
@@ -24,7 +24,6 @@ DevToolsModules(
     'MountainGraphWidget.js',
     'ShapesInContextEditor.js',
     'SideMenuWidget.jsm',
-    'SimpleListWidget.jsm',
     'Spectrum.js',
     'TableWidget.js',
     'TreeWidget.js',
diff --git a/devtools/client/shared/widgets/view-helpers.js b/devtools/client/shared/widgets/view-helpers.js
index 80d13f20df3c..581158a08827 100644
--- a/devtools/client/shared/widgets/view-helpers.js
+++ b/devtools/client/shared/widgets/view-helpers.js
@@ -474,8 +474,6 @@ Item.prototype = {
  *   });
  *
  * See https://gist.github.com/victorporof/5749386 for more details.
- * The devtools/shared/widgets/SimpleListWidget.jsm is an implementation
- * example.
  *
  * Language:
  *   - An "item" is an instance of an Item.
diff --git a/devtools/client/shared/widgets/widgets.css b/devtools/client/shared/widgets/widgets.css
index 252c56c103e3..1eca655c7ee7 100644
--- a/devtools/client/shared/widgets/widgets.css
+++ b/devtools/client/shared/widgets/widgets.css
@@ -13,13 +13,6 @@
   -moz-user-focus: normal;
 }
 
-/* SimpleListWidget */
-
-.simple-list-widget-container {
-  overflow-x: hidden;
-  overflow-y: auto;
-}
-
 /* FastListWidget */
 
 .fast-list-widget-container {
diff --git a/devtools/client/themes/widgets.css b/devtools/client/themes/widgets.css
index 33fd2edf7a9d..ab3010e1cb66 100644
--- a/devtools/client/themes/widgets.css
+++ b/devtools/client/themes/widgets.css
@@ -101,36 +101,6 @@
   }
 }
 
-/* SimpleListWidget */
-
-.simple-list-widget-container {
-  /* Hack: force hardware acceleration */
-  transform: translateZ(1px);
-}
-
-.simple-list-widget-item.selected {
-  background-color: var(--theme-selection-background);
-  color: var(--theme-selection-color);
-}
-
-.theme-dark .simple-list-widget-item:not(.selected):hover {
-  background-color: rgba(255,255,255,.05);
-}
-
-.theme-light .simple-list-widget-item:not(.selected):hover {
-  background-color: rgba(0,0,0,.05);
-}
-
-.simple-list-widget-empty-text,
-.simple-list-widget-perma-text {
-  padding: 4px 8px;
-}
-
-.simple-list-widget-empty-text,
-.simple-list-widget-perma-text {
-  color: var(--theme-body-color-alt);
-}
-
 /* FastListWidget */
 
 .fast-list-widget-container {