Joseph Cullen (born 13 July 1989) is an English professional darts player who competes in Professional Darts Corporation (PDC) events, where he is currently ranked world number thirty-one. A PDC Tour Card holder since 2011, Cullen won his first PDC major title at the 2022 Masters, and finished as runner-up in the 2022 Premier League Darts. Cullen has won 12 PDC ranking titles in his professional career, including three European Tour titles.

In his youth career, Cullen won three PDC Youth Tour titles in 2011.

Cullen first came to prominence in 2008 when he qualified for the UK Open. He defeated Mark Stapleton and Dennis Smith before Chris Mason defeated him in the last 64. Following his performances at Bolton, he joined the PDC circuit. He also reached the final of the New Kids on the Oche tournament, losing to Arron Monk.

Cullen had another decent run at the 2010 UK Open. He knocked out Darren Latham and Mike Nott before losing to Mervyn King, again in the last 64. Later that year, he defeated Phil Taylor in the last 16 of the John McEvoy Gold Dart Classic in Killarney, eventually losing in the quarter-finals to Colin Osborne.

Cullen qualified for his first PDC World Darts Championship in 2011. He lost narrowly to Terry Jenkins 3–2 in sets in the first round. In April, Cullen reached his first PDC Pro Tour final at the sixth UK Open Qualifier in Barnsley, losing 6–1 to Taylor.

Cullen reached the final of the PDPA World Championship Qualifier, where he was beaten by Arron Monk 5–3. The result meant that he qualified for the preliminary round of the 2012 World Championship, where he beat Oliver Ferenc 4–2 in legs. He played the 10th seed Terry Jenkins in the first round for the second successive year and was beaten 3–0, winning just three legs in the match. In April, he earned a place in the Austrian Darts Open by defeating Sam Hill and John Bowles in the UK qualifier. He played Brendan Dolan in the first round and won 6–4, and then continued his run by beating Simon Whitlock 6–4, despite his opponent hitting a nine darter. Cullen defeated Mark Walsh to make the quarter-finals, where he was this time on the wrong end of a 6–4 scoreline as he lost to eventual winner Justin Pipe. Cullen's best result of the season came a week after this as he won through to the semi-finals of the final UK Open Qualifier, but was then whitewashed 6–0 by Pipe. He also qualified for the third European Tour event, the European Darts Open and beat Jenkins 6–1 in the first round in Düsseldorf, before losing to Johnny Haines 6–5 in round two.

Cullen reached the last 16 of the UK Open with victories over Jim Walker (9–4) and Colin Lloyd (9–8), but then let a 4–0 and 5–1 lead against Jamie Caven slip to lose 9–8. He qualified for the World Matchplay for the first time and lost to Pipe 10–4 in the first round.

Cullen qualified for the 2013 World Championship by finishing 36th on the 2012 ProTour Order of Merit, claiming the fifth of sixteen spots that were available for the highest non-qualified players. He lost 3–0 to John Part in the first round, with the Canadian's superior finishing being the difference between the players. Cullen was ranked world number 41 after the tournament. He lost 9–5 to Lee Palfreyman in the third round of the UK Open. At the Austrian Darts Open Cullen beat Kim Huybrechts 6–4 and then averaged a stunning 111.84 three-dart average in seeing off Stuart Kellett 6–1. He reached the quarter-finals of this event for the second year running by surviving one match dart from Raymond van Barneveld to win 6–5, but was then beaten 6–0 by Mervyn King. Cullen reached three other quarter-finals in floor events during the year but lost in each one.