template content

Finally, click the Save Template located at the top of the page:

save template

Change Your Magento 2 Email Template

Now navigate to STORES → Configuration and click on Contacts under the Generaltab:

general-contacts

Go to the Email Options section, select My Contact Form from Email Template drop-down option:

select email template

To end the process, click the Save Config button at the top of the page:
save config

To see the new modified form in action, go to the Contact form where you will see the new field Subject:

contact field Magento 2 - Result

Wrapping Up

Adding custom fields to contact forms adds the element of personalization that goes a long way in converting visitors into customers. I hope you are now able to add custom fields to your Magento 2 contact forms. If you need help, just drop a comment below.