Cardiff boss Corniel van Zyl said: “We are really pleased that Alex has decided to continue his journey at Cardiff, particularly on the back of such an impressive season so far, most recently with Wales in the Six Nations where he put in some big performances.
“He has been brilliant for Cardiff during my time at the club. It is very clear that he really cares about the club, his team-mates and the people we represent.
“On the pitch, he clearly has an all-in mentality. He puts his body on the line, is very versatile and has an all-round game where he can make an impact on both sides of the ball.”
Mann, 24, has been an important part of Steve Tandy’s Wales side, having been selected in all nine of his XVs this season – hooker Dewi Lake is the only other player to match that.
The former Wales Under-20 captain made a statement performance in Wales’ 27-17 defeat by Ireland in Dublin when he set a Six Nations record by making 33 tackles.
His display earned the praise of Wales assistant coach Dan Lydiate, who said: “He is some talent and is a young man with a hell of an engine who reads the game really well on both sides of the ball.”
