The 38-year-old's days at the club appeared to be numbered when manager Roberto Martinez brought in Vladimir Stojkovic on loan from Sporting Lisbon in January to be Chris Kirkland's deputy.
However, the Serbian played six matches, never kept a clean sheet and put in a number of shaky performances.
Pollitt played just once after Stojkovic's arrival - the disastrous 8-0 defeat at Chelsea on the final day of the season - but Martinez wants the veteran around next season.
"Mike is a terrific goalkeeper first and foremost with great experience, and he continues to set standards on a daily basis that the younger players can follow," said the Latics boss.
"He has been patient during his time at the club, but has never been anything less than totally professional and committed to the club.
"He is also an infectious character who is great to have around the dressing room and we are all delighted to have him back."
Pollitt said he hoped he could extend his term at the club longer by going into coaching.
"I'm delighted to be at the club for another year - my sixth at the club all together. It's a great feeling," he said
"I work hard every day, do the best I can, and when I do get a game I make sure I'm ready to try to impress the manager.
"Although he likes me round the place, I think more importantly he rates me as a goalkeeper.
"I've started earning my (coaching) badges and hopefully I'll get the goalkeeping qualifications I need to become a coach.
"But, for the time being, I'm still concentrating on what I can still bring as a player."