42-year-old Penn -- a UFC Hall of Famer -- threw his hat in the proverbial ring (Octagon?) this week, and even laid out several policies he would immediately overturn.

"As soon as I step into Hawaii's Governor office I will remove all new federal and state mandates that have been hurting our economy, residents, and 'ohana," BJ wrote.

"We will get the best doctors, medicines, therapies, and health care the world has to offer to fight this pandemic and always keep Hawaii among the safest and healthiest states in the union."

Penn -- who last fought in the UFC in 2019 -- also vowed to ax the policy mandating people traveling to the state must be vaxxed, writing ... "We will get rid of all vaccine passports. Hawaii will be vaccinated with Aloha and unvaccinated with Aloha policy for everyone."

On masks? Similar deal.

"Same with the masks 😷. We will follow the constitution to the tee 👌. I am not here to fit in with the other politicians, I am here to get our freedoms back!"

Of course, BJ's had several run-ins with the law over the last few years ... but the MMA great isn't hiding from his past, addressing it head-on.

"I've made a lot of mistakes in my life but I would never run from a fight, or sell out my people."

Democrat, David Ige, is the current sitting gov of Hawaii. His term ends late next year.