[5] After joining Crystal Palace at the age of 13, he was handed his debut in a 3–0 home win against Walsall in the League Cup on 23 August 2005.

[10] The loan deal was extended a day before it was due to expire on 15 September, keeping Grabban at Oldham for another month.

[17] A week later he played in his final game before joining Millwall, a 2–0 win against Bristol City at Selhurst Park.

[18] On 21 January 2008, Grabban signed for Palace's London rivals Millwall for £150,000 on a three-and-a-half-year contract, and he was assigned the shirt number 10.

His goal at the time had given Millwall a 3–1 lead, however Oldham sensationally managed to come back and win the game 4–3.

[32] Millwall and Grabban did gain promotion via the playoffs during the 2009–10 season after winning the 2010 Football League One play-off final against Swindon Town.

[49] He made his debut on 6 August, and scored a stunning volley with the outside of his foot from the edge of the box, as Rotherham beat Oxford United 1–0 at Don Valley Stadium.

[50] He scored his second goal for the club on 27 August in a 3–0 home win against Gillingham, taking Rotherham to the top of the league in the process.

[91] After making his debut in a 1–0 loss to Wolves in the opening game of the season,[92] Grabban scored his first goal for the club in his second appearance, helping Norwich to beat Watford 3–0 at Carrow Road.

In August 2015, Grabban was suspended by Norwich after he did not report for their League Cup fixture against Rotherham United, despite being named as a substitute for the match.

[97] On 11 January 2016, Grabban re-signed for now Premier League side AFC Bournemouth from Norwich City on a three-and-a-half-year deal for an undisclosed fee.

[98] Grabban struggled to make an impact for Bournemouth on returning to the club, failing to score in 16 appearances in the second half of the 2015–16 season.

[101] Grabban scored three goals in 17 appearances for Reading throughout his loan spell, and he featured in their Championship play-off final defeat to Huddersfield Town.

[111] Grabban also finished the runner up to Sky Bet Championship Golden Boot winner Matěj Vydra after scoring 20 goals in the competition (for both Aston Villa and Sunderland combined) during the 2017–18 season.

[112] Grabban then joined Championship side Nottingham Forest for an undisclosed fee (believed to be £6 million) on 6 July 2018 on a four-year deal.

Manager Aitor Karanka revealed that it took two to three weeks of persuasion before Grabban chose to move to Forest, but eventually he was convinced of the club's ambition.

[114] Grabban then did not score in his next five games and picked up a few niggling injuries, before Karanka was sacked and replaced with Forest club legend Martin O'Neill.

[119] Grabban was made vice-captain of Nottingham Forest ahead of the new season, following the departure of Ben Watson to Charlton Athletic.

[120] Although he did manage to score on his return in a 2–0 victory over Sheffield Wednesday,[122] he struggled to get a consistent run of games in the Forest team due to competition with strikers Lyle Taylor and Glenn Murray.

Grabban finished the season with 13 goals in 34 appearances, with an ankle injury keeping him out of the side for much of the second half of the campaign.

During that time, he was given credit for acting as a mentor to Keinan Davis and helping the loanee to improve his movement and positioning.

As club captain, Grabban lifted the play-off trophy alongside Joe Worrall as Forest were promoted to the Premier League for the first time in 23 years.

[123] Grabban's Forest contract ran out on 30 June and his time at the club came to an end when it was announced he had turned down the offer of a new one.

In May 2014, it was reported on TV Jamaica that he was called up by German coach Winfried Schäfer to play against Serbia on 26 May 2014 in an international friendly.

Grabban was later called up to the Jamaica national football team on 27 February 2015 for friendly games against Venezuela and Cuba.