govuk-frontend/dist/govuk/components/select/template-default.html

GOV.UK Frontend contains the code you need to start building a user interface for government platforms and services.

<div class="govuk-form-group">
  <label class="govuk-label" for="select-1">
    Label text goes here
  </label>
  <select class="govuk-select" id="select-1" name="select-1">
    <option value="1">GOV.UK frontend option 1</option>
    <option value="2" selected>GOV.UK frontend option 2</option>
    <option value="3" disabled>GOV.UK frontend option 3</option>
  </select>
</div>