This is a question which I came across on the success community and which made me realise that it could be something which admins always look for an answer. Through this blog post I am going to give a simple solution which can even used by a Salesforce Admin who is not good with code. If you are a Salesforce Admin then you simple need to follow these steps.
- Go to Web-to-Lead Setup and click Create Web-to-Lead Form button
- Select the fields which you want see on the web form including State/Province and Country
JSFiddle to the Web-to-lead form with state and country dependent pick list fields.
I hope it helps!!