The Turkey international joins on a season-long loan with a view to a permanent deal and becomes Rovers' eighth summer signing.
Kazim-Richards, who has 36 international caps, has been on trial at Ewood Park since the pre-season trip to the Netherlands and after finalising his loan switch will feature in Rovers' final friendly against Cork on Sunday.
The 25-year-old started his career with Bury, before enjoying short spells with Brighton and Sheffield United and in June 2007 he joined Turkish side Fenerbahce, who he helped reach the Champions League quarter-finals a year later, scoring in the 2-1 first-leg victory over Chelsea.
He scored the first derby goal in Galatasaray's new stadium against his former club and spent the second half of last season on loan at Olympiacos, where he won the league and cup double.
Meanwhile, Sheffield United have signed Blackburn striker Nick Blackman for an undisclosed fee.
The 22-year-old has penned a two-year deal, with the option of a third, at Bramall Lane.
He becomes the sixth new arrival at the club during the summer, following Darryl Westlake, John Cofie, Matt Hill, Tony McMahon and Shaun Miller.
Blackman joined Blackburn in 2009 after starting his career as a trainee at Macclesfield.
The young forward scored 10 goals in 18 league appearances during a loan spell at Motherwell last year and has also had similar stints at Blackpool, Oldham and Aberdeen.