The vastly experienced frontman makes a quick return to Rovers, signing a two-year deal following his release from Queens Park Rangers.
The 31-year-old arrived on loan at Ewood Park towards the end of last term, but his spell was cut short due to a foot injury.
Rovers boss Gary Bowyer was delighted to welcome Campbell back to the club: "He's a player who has huge experience and is a proven goalscorer at this level.
"He feels he has some unfinished business with the club and is hungry to succeed.
"He will add a different dimension to our attacking options and he is the right character we want to have on board."
Starting out in non-league, Campbell got his big break in professional football when he signed for Brentford in June 2005. After impressing with the Bees, he was quickly snapped up by the Blues in a £500,000 move to Birmingham City.
By July 2007 the striker was on his way to Leicester City in a £1.6m move, but following the Foxes' relegation he went on loan to both Blackpool and Derby County, before returning to the Seasiders in a permanent deal in August 2010.
After scoring 13 goals in 31 games for Blackpool in the Premier League, QPR secured his services the following summer, but an injury-hit year restricted his appearances.
In October 2012, the forward went on loan to Championship side Ipswich Town, where he quickly rediscovered his goalscoring form, netting 10 times in a 17-match spell.
That record prompted former Rovers manager Michael Appleton to make a move for Campbell in February, with the striker making seven appearances, before returning to Loftus Road in March with a broken bone in his foot.
Campbell is Gary Bowyer's fifth signing of the summer following the arrivals of Simon Eastwood, Chris Taylor, Alan Judge and Todd Kane, and will be in the squad for Saturday's match against Wrexham.