General manager Reggie McKenzie announced the deal with the eight-year veteran on Friday, a day after Kluwe told FoxSports.com that he had signed with the team.
"I'm excited to be an Oakland Raider and be playing in California. Now, my family can actually come to games," Kluwe, who went to high school in Southern California and played in college at UCLA, told the website Thursday.
Kluwe played in 127 games for the Minnesota Vikings with a 44.4-yard career average. He ranks second all time in Minnesota history with a 37.3-yard net average.
Lechler left Oakland as a free agent this offseason after spending the past 13 years with the Raiders. Oakland released punter Bobby Cowan but still has Marquette King on the roster. King impressed the team in training camp last summer and spent the year on injured reserve.
During his time with the Vikings, Kluwe earned a reputation as one of the most opinionated players in the league. He criticized union leadership during the lockout, wore a patch on his uniform to protest the lack of punters in the Hall of Fame and, most notably, became a vocal supporter of gay rights, penning a number of thoughtful, and occasionally profane, columns on the issue for various websites. He also plays in a rock band in his spare time and is an avid video gamer.
"I'm still going to be myself socially and continue to tweet and interact with my fans," Kluwe told the website Thursday.
Information from The Associated Press was used in this report.