On 20 July 2011, Tarver took on Australian IBO cruiserweight champion Danny Green at the Sydney Entertainment Centre, Sydney, New South Wales, Austrailia, in Tarver's debut in the 200 lb cruiserweight division.
Tarver dominated the fight, knocking Green down in the second round and controlling the majority of the action from there on in. After taking heavy punishment and being saved by the bell at the end of round 9, Green failed to come out for the start of round 10, allowing Tarver to take the victor and the title by TKO.
Following the rematch loss to Dawson, Tarver took over a year off from the ring, before returning on 15 October 2010 to defeat Nagy Aguilera by a 10 round unanimous decision in a bout that took place in the heavyweight division. For this fight Tarver officially weighed 221 lbs, some 46 lbs more than he had weighed for the Dawson rematch.
On February 25, 2021, it was announced that Tarver would be returning to the ring for the first time since 2015. He was signed to face former UFC Heavyweight Champion Frank Mir in Mir's boxing debut on April 17 on the undercard of Jake Paul vs. Ben Askren. Tarver intended to represent mental health advocacy and has said he would dedicate the bout with Mir to all survivors or victims of mental health disorders. However, on March 23, it was announced that Tarver had withdrawn from the bout after not being cleared by the Georgia Athletic & Entertainment Commission. He was replaced by former IBG cruiserweight champion Steve Cunningham.
Tarver starred as heavyweight champion Mason "The Line" Dixon in the 2006 film Rocky Balboa. In the film, the current, unpopular champion Dixon fights former champion Rocky Balboa, who decides to come out of retirement. Dixon wins the match by split decision, and after breaking his hand in the second round of the bout but still managing to stand toe to toe with Rocky for the full 10 rounds, proves to doubters that he has the heart of a champion. The DVD of the movie offers an alternate ending, in which Rocky wins the split decision. Dixon's record before the fight is 33-0 (33 KO). Also on the DVD, the film's writer and director Sylvester Stallone wanted to cast a real boxer in the role of Dixon, as he thought it would be easier to teach a boxer how to act than to teach an actor how to box convincingly. Tarver is one of only three fighters to actually defeat "Rocky Balboa" in film.
After his loss to Dawson in June, 2012, Tarver served as a boxing analyst for Showtime Champion Boxing.