"I have sent my resignation to President Pranab Mukherjee," Sankaranarayanan told media persons at Raj Bhavan here.
Justifying his decision, the 82-year-old Congress leader said he had "respected the Constitution" by submitting his resignation.
"During my tenure here as governor, and even earlier in Jharkhand and Nagaland, I never brought politics into my functioning," Sankaranarayanan said.
In a veiled attack on the Narendra Modi government's decision to transfer him to Mizoram, he said: "No government is permanent, no individuals are permanent and they have to change some time."
Sankaranarayanan, who was re-appointed Maharashtra governor in 2012, thanked the people of the state for all their love and support during his tenure.
He added that from Monday, he would work only as a Congressman, the party which he had joined decades ago as a grassroots leader in Kerala, and later risen up the ranks.
"From tomorrow, I shall have no restrictions, I can do whatever I want, go wherever I want and speak on any topic," he said in a cheerful and relaxed mood.
A Congress veteran from Kerala, Sankaranarayanan, who was transferred as Maharashtra governor in 2010, was re-appointed for a second term in 2012. Earlier, he served stints in Jharkhand and Nagaland for three years.
Gujarat Governor Om Prakash Kohli has been given additional charge of Maharashtra.