No, you do not need a passport to visit the Isle of Wight. It's really that simple. The Isle of Wight is part of the United Kingdom, so if you're a UK citizen, you can visit the Isle of Wight freely.
If you're coming from outside the UK, make sure you have your passport and any necessary visas for entry to the UK. Then you're free to travel to the Isle of Wight.
Enjoy your trip to the Isle of Wight!
------------------------------
If you're wanting to travel over via boat, check our article for routes from mainland UK to the Isle of Wight.