diff --git a/packages/netlify-cms-locales/src/en/index.js b/packages/netlify-cms-locales/src/en/index.js
index 0f488489..1e01bbe6 100644
--- a/packages/netlify-cms-locales/src/en/index.js
+++ b/packages/netlify-cms-locales/src/en/index.js
@@ -52,6 +52,10 @@ const en = {
         range: '%{fieldLabel} must be between %{minValue} and %{maxValue}.',
         min: '%{fieldLabel} must be at least %{minValue}.',
         max: '%{fieldLabel} must be %{maxValue} or less.',
+        rangeCount: '%{fieldLabel} must have between %{minCount} and %{maxCount} item(s).',
+        rangeCountExact: '%{fieldLabel} must have exactly %{count} item(s).',
+        minCount: '%{fieldLabel} must be at least %{minCount} item(s).',
+        maxCount: '%{fieldLabel} must be %{maxCount} or less item(s).',
       },
     },
     editor: {
diff --git a/packages/netlify-cms-widget-select/src/SelectControl.js b/packages/netlify-cms-widget-select/src/SelectControl.js
index 9cd42eeb..69bcad05 100644
--- a/packages/netlify-cms-widget-select/src/SelectControl.js
+++ b/packages/netlify-cms-widget-select/src/SelectControl.js
@@ -2,7 +2,7 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import { Map, List, fromJS } from 'immutable';
-import { find } from 'lodash';
+import { find, isNumber } from 'lodash';
 import Select from 'react-select';
 import { reactSelectStyles } from 'netlify-cms-ui-default';
 
@@ -55,6 +55,55 @@ export default class SelectControl extends React.Component {
     }),
   };
 
+  isValid = () => {
+    const { field, value, t } = this.props;
+    const min = field.get('min');
+    const max = field.get('max');
+    if (!field.get('multiple')) {
+      return { error: false };
+    }
+    if ([min, max].every(isNumber)) {
+      const isValid = value && value.size >= min && value.size <= max;
+      const messageKey = min === max ? 'rangeCountExact' : 'rangeCount';
+      if (!isValid) {
+        return {
+          error: {
+            message: t(`editor.editorControlPane.widget.${messageKey}`, {
+              fieldLabel: field.get('label', field.get('name')),
+              minValue: min,
+              maxValue: max,
+            }),
+          },
+        };
+      }
+    } else if (isNumber(min)) {
+      const isValid = value && value.size >= min;
+      if (!isValid) {
+        return {
+          error: {
+            message: t('editor.editorControlPane.widget.rangeMin', {
+              fieldLabel: field.get('label', field.get('name')),
+              minValue: min,
+            }),
+          },
+        };
+      }
+    } else if (isNumber(max)) {
+      const isValid = !value || value.size <= max;
+      if (!isValid) {
+        return {
+          error: {
+            message: t('editor.editorControlPane.widget.rangeMax', {
+              fieldLabel: field.get('label', field.get('name')),
+              maxValue: max,
+            }),
+          },
+        };
+      }
+    }
+    return { error: false };
+  };
+
   handleChange = selectedOption => {
     const { onChange, field } = this.props;
     const isMultiple = field.get('multiple', false);
diff --git a/packages/netlify-cms-widget-select/src/__tests__/select.spec.js b/packages/netlify-cms-widget-select/src/__tests__/select.spec.js
index d40d3e6c..0fabd204 100644
--- a/packages/netlify-cms-widget-select/src/__tests__/select.spec.js
+++ b/packages/netlify-cms-widget-select/src/__tests__/select.spec.js
@@ -34,7 +34,7 @@ class SelectController extends React.Component {
 }
 
 function setup({ field, defaultValue }) {
-  let renderArgs;
+  let renderArgs, ref;
   const stateChangeSpy = jest.fn();
   const setActiveSpy = jest.fn();
   const setInactiveSpy = jest.fn();
@@ -52,6 +52,8 @@ function setup({ field, defaultValue }) {
             classNameWrapper=""
             setActiveStyle={setActiveSpy}
             setInactiveStyle={setInactiveSpy}
+            ref={widgetRef => (ref = widgetRef)}
+            t={jest.fn(msg => msg)}
           />
         );
       }}
@@ -66,6 +68,7 @@ function setup({ field, defaultValue }) {
     stateChangeSpy,
     setActiveSpy,
     setInactiveSpy,
+    ref,
     input,
   };
 }
@@ -207,4 +210,81 @@ describe('Select widget', () => {
       expect(getByText('baz')).toBeInTheDocument();
     });
   });
+  describe.only('validation', () => {
+    function validate(setupOpts) {
+      const { ref } = setup(setupOpts);
+      const { error } = ref.isValid();
+      return error?.message;
+    }
+    it('should fail with less items than min allows', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, min: 1 }),
+      };
+      expect(validate(opts)).toMatchInlineSnapshot(`"editor.editorControlPane.widget.rangeMin"`);
+    });
+    it('should fail with more items than max allows', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, max: 1 }),
+        defaultValue: fromJS([stringOptions[0], stringOptions[1]]),
+      };
+      expect(validate(opts)).toMatchInlineSnapshot(`"editor.editorControlPane.widget.rangeMax"`);
+    });
+    it('should enforce min when both min and max are set', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, min: 1, max: 2 }),
+      };
+      expect(validate(opts)).toMatchInlineSnapshot(`"editor.editorControlPane.widget.rangeCount"`);
+    });
+    it('should enforce max when both min and max are set', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, min: 1, max: 2 }),
+        defaultValue: fromJS([stringOptions[0], stringOptions[1], stringOptions[2]]),
+      };
+      expect(validate(opts)).toMatchInlineSnapshot(`"editor.editorControlPane.widget.rangeCount"`);
+    });
+    it('should enforce min and max when they are the same value', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, min: 2, max: 2 }),
+        defaultValue: fromJS([stringOptions[0], stringOptions[1], stringOptions[2]]),
+      };
+      expect(validate(opts)).toMatchInlineSnapshot(
+        `"editor.editorControlPane.widget.rangeCountExact"`,
+      );
+    });
+    it('should pass when min is met', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, min: 1 }),
+        defaultValue: fromJS([stringOptions[0]]),
+      };
+      expect(validate(opts)).toBeUndefined();
+    });
+    it('should pass when max is met', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, max: 1 }),
+        defaultValue: fromJS([stringOptions[0]]),
+      };
+      expect(validate(opts)).toBeUndefined();
+    });
+    it('should pass when both min and max are met', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, min: 2, max: 3 }),
+        defaultValue: fromJS([stringOptions[0], stringOptions[1]]),
+      };
+      expect(validate(opts)).toBeUndefined();
+    });
+    it('should pass when both min and max are met, and are the same value', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, multiple: true, min: 2, max: 2 }),
+        defaultValue: fromJS([stringOptions[0], stringOptions[1]]),
+      };
+      expect(validate(opts)).toBeUndefined();
+    });
+    it('should not fail on min/max if multiple is not true', () => {
+      const opts = {
+        field: fromJS({ options: stringOptions, min: 2, max: 2 }),
+        defaultValue: fromJS([stringOptions[0]]),
+      };
+      expect(validate(opts)).toBeUndefined();
+    });
+  });
 });
diff --git a/website/content/docs/widgets/select.md b/website/content/docs/widgets/select.md
index 5754222b..400464e9 100644
--- a/website/content/docs/widgets/select.md
+++ b/website/content/docs/widgets/select.md
@@ -16,6 +16,8 @@ The select widget allows you to pick a string value from a dropdown menu.
       - string values: the label displayed in the dropdown is the value saved in the file
       - object with `label` and `value` fields: the label displays in the dropdown; the value is saved in the file
   - `multiple`: accepts a boolean; defaults to `false`
+  - `min`: minimum number of items; ignored if **multiple** is not `true`
+  - `max`: maximum number of items; ignored if **multiple** is not `true`
 - **Example** (options as strings):
     ```yaml
     - label: "Align Content"
@@ -42,4 +44,14 @@ The select widget allows you to pick a string value from a dropdown menu.
       options: ["Design", "UX", "Dev"]
       default: ["Design"]
     ```
-
+- **Example** (min/max):
+    ```yaml
+    - label: "Tags"
+      name: "tags"
+      widget: "select"
+      multiple: true
+      min: 1
+      max: 3
+      options: ["Design", "UX", "Dev"]
+      default: ["Design"]
+    ```