"Going back to his days at the University of Miami, Andre was one of the most impressive wide receivers I've scouted," Titans general manager Jon Robinson said in a statement. "He had a professional approach to the game both on and off the field and in my opinion is one of the best to have played the game. I enjoyed getting to know and work with him in his time with our team."
A seven-time Pro Bowler with the Houston Texans, Johnson had been a backup on the Titans' depth chart this season. He had nine receptions for 85 yards and two touchdowns in 2016 but hadn't made a catch since Week 5 against the Miami Dolphins.
Johnson made his legacy in Houston, where he is by far the franchise leader in receiving yards, receptions and receiving touchdowns.
The 35-year-old steps away 10th in the NFL in career receiving yards (14,185) and ninth in career receptions (1,062).
Texans owner Bob McNair told the Houston Chronicle that he would "love" to see Johnson in the Hall of Fame.
"That would be terrific. I think he deserves to be there," McNair said. "It'd be a reflection on what we have done with our franchise in that we've produced a player who was of that quality."
Texans linebacker Brian Cushing said Monday he was "shocked" to hear that his former teammate was retiring.
Texans receiver DeAndre Hopkins, when asked whether in his mind Johnson is a Hall of Famer, said: "In everybody's mind, not just mine."
Hopkins, who now is one of the NFL's top receivers, remembered Johnson mentoring him in his first few seasons.
"It was very big to have a guy of his status and who has played a lot of football to teach me a lot of things about the game of football and about life in general. He basically groomed me my first couple years I was here," he said.
Running back Arian Foster, Johnson's longtime teammate in Houston, also announced his retirement last week.
Johnson led the NFL in receptions in 2006 (103 catches) and 2008 (115). He topped the league with 1,575 receiving yards in 2008 and 1,569 yards in 2009, two of his seven seasons with more than 1,000 yards.
He bounced around the AFC South after being released by the Texans after the 2014 season. He played one season for the Indianapolis Colts in 2015 and joined the Titans this offseason.
ESPN's Sarah Barshop contributed to this report.