The 36-year-old reliever issued a statement through the team saying he wanted to spend more time with his family and faith.
Torres also told the Milwaukee Journal Sentinel that Brewers GM Doug Melvin was very understanding of his decision.
"I had a wonderful experience in Milwaukee but he knows I am serious about it," Torres told the newspaper.
Torres was 7-5 with a 3.49 ERA and a career-high 28 saves in 71 relief appearances last season. He had a 44-58 career record with a 4.31 ERA and 57 saves for San Francisco, Seattle, Montreal, Pittsburgh and Milwaukee.
Torres remains on the roster of the Brewers, who have until Saturday to exercise a $3.75 million option with a $300,000 buyout.
"I wanted to make it easy for [Melvin]," Torres told the Journal Sentinel. "I already had made up my mind and wanted to tell him this was my last season."
Torres added that while it was "a given" that Milwaukee would exercise the option, he was ready to retire now.
"It's a small sacrifice I'm making," Torres told the newspaper. "I know I'm doing the right thing. It might be a surprise to a lot of people and some might not understand, especially from a money standpoint. That shows you how determined I am to lead by life in another way."
He may file provisionally for free agency through Thursday.
Information from The Associated Press contributed to this report.