Fisher, who has more tenure than any current coach in the NFL, has been with the Titans since 1995. He is among the top 20 on the league's all-time victory list.
"Jeff shares my expectations," Adams said in a statement. "The results of his leadership have been some very good football teams and I believe he will get us back to an elite level."
Adams had announced two days earlier that the team was parting ways with quarterback Vince Young, whose relationship with Fisher had soured during the 2010 season.
"Mr. Adams and I had a good talk about where we are as a football team," Fisher said. "Clearly I am pleased with the news today. Presenting Mr. Adams with his first Lombardi Trophy is still the objective and I will continue to work for that goal."
The Titans went 6-10 this season, their first losing campaign in five years. They lost eight of their last nine games.
Fisher has a career record of 147-126 and led the team to a division title two years ago. He took the Titans to their only Super Bowl at the end of the 1999 season, when they lost 23-16 loss to St. Louis.