diff --git a/packages/ui-components/src/components/UIComboBox/UIComboBox.tsx b/packages/ui-components/src/components/UIComboBox/UIComboBox.tsx
index f9400f6cab..aaf0723c2d 100644
--- a/packages/ui-components/src/components/UIComboBox/UIComboBox.tsx
+++ b/packages/ui-components/src/components/UIComboBox/UIComboBox.tsx
@@ -146,12 +146,27 @@ export class UIComboBox extends React.Component<UIComboBoxProps, UIComboBoxState
         this.onScrollToItem = this.onScrollToItem.bind(this);
         this.setFocus = this.setFocus.bind(this);
         this.onRenderIcon = this.onRenderIcon.bind(this);
+        this.updateAriaInvalid = this.updateAriaInvalid.bind(this);
 
         initializeComponentRef(this);
 
         this.state = {};
     }
 
+    /**
+     * Called when component did initialize.
+     */
+    componentDidMount(): void {
+        this.updateAriaInvalid();
+    }
+
+    /**
+     * Called when component is rerendered.
+     */
+    componentDidUpdate(): void {
+        this.updateAriaInvalid();
+    }
+
     /**
      *
      * @param {UIComboBoxProps} nextProps
@@ -165,6 +180,18 @@ export class UIComboBox extends React.Component<UIComboBoxProps, UIComboBoxState
         return true;
     }
 
+    /**
+     * This is a workaround for FluentUI not handling aria-invalid correctly for a ComboBox.
+     * For the time being we add logic here to set aria-invalid based on the presence of
+     * an errorMessage.
+     */
+    private updateAriaInvalid(): void {
+        const htmlInputField = this.comboboxDomRef.current?.getElementsByClassName('ms-ComboBox-Input').item(0);
+        if (htmlInputField) {
+            htmlInputField.ariaInvalid = this.props.errorMessage !== undefined ? 'true' : 'false';
+        }
+    }
+
     /**
      * Updates hidden options.
      *
diff --git a/packages/ui-components/stories/UICombobox.story.tsx b/packages/ui-components/stories/UICombobox.story.tsx
index 17ad0facaf..3c1e796a09 100644
--- a/packages/ui-components/stories/UICombobox.story.tsx
+++ b/packages/ui-components/stories/UICombobox.story.tsx
@@ -154,6 +154,47 @@ export const MultiSelectSearchHighlight = (): JSX.Element => {
     );
 };
 
+export const DynamicError = () => {
+    const [selectedKey, setSelectedKey] = React.useState<string | number>('OK');
+    const selectOptions = [
+        {
+            key: 'OK',
+            text: 'No Error Message'
+        },
+        {
+            key: 'ERROR',
+            text: 'With Error Message'
+        }
+    ];
+
+    function onCbChange(
+        event: React.FormEvent<IComboBox>,
+        option?: IComboBoxOption | undefined,
+        index?: number | undefined,
+        value?: string | undefined
+    ) {
+        if (option) {
+            setSelectedKey(option.key);
+        }
+    }
+
+    return (
+        <div style={{ width: '300px' }}>
+            <UIComboBox
+                options={selectOptions}
+                label="Dynamic Validation Error"
+                highlight={true}
+                allowFreeform={true}
+                useComboBoxAsMenuMinWidth={true}
+                autoComplete="on"
+                selectedKey={selectedKey}
+                onChange={onCbChange}
+                errorMessage={selectedKey === 'OK' ? undefined : 'Error Message'}
+            />
+        </div>
+    );
+};
+
 export const Messages = (): JSX.Element => (
     <div style={{ width: '300px' }}>
         <UIComboBox
@@ -163,7 +204,7 @@ export const Messages = (): JSX.Element => (
             allowFreeform={true}
             useComboBoxAsMenuMinWidth={true}
             autoComplete="on"
-            errorMessage="Dummy Error"
+            errorMessage={'Dummy Error'}
         />
         <UIComboBox
             options={data}