The Scotland international scored 73 goals for the Terriers in three years at the club has signed a five-year deal with Rovers, who are looking to bounce back to the Premier League after suffering relegation last season.
Rhodes struck 36 times in League One last season alone, to fire Huddersfield to promotion via the play-offs and Blackburn manager Steve Kean hopes he can have a similar impact at Ewood Park.
He told the clubs official website: "Jordan is a top class striker and we are absolutely delighted to bring him in.
"His record is there for all to see and I believe he can play a major role in our drive for promotion back to the Premier League."
Rhodes has started this season with three goals in three games for club and country, including his first senior international goal for Scotland against Australia.The 22-year-old will go straight into the club's squad for this weekend’s trip to Elland Road to face Leeds United.