The wide receiver, 33, has been granted permission by the Texans to seek a trade after he was told his role in their offense would be reduced.
Johnson posted a farewell message on his Instagram account that read: “Thank you Houston for a wonderful 12 years.
“And a special thanks to all the fans who have supported me throughout my career.”
Agent Kennard McGuire later added: “It’s been an amazing journey for Andre – and to watch how the city of Houston has embraced him and watch him become the class act that personified true professionalism.”
Johnson was selected by the Texans with the third overall pick in the 2003 NFL Draft and has spent his entire career with the team.
The seven-time Pro Bowler owns all of the franchise records in receiving categories and caught 85 passes for 936 yards last season, scoring three touchdowns.
But the emergence of DeAndre Hopkins as their No 1 receiver last season meant Johnson would most likely find targets harder to come by in future campaigns as he winds down his glittering career.
Johnson has two years remaining on his contract and has a salary cap figure of $16.1m next season.