Alex Foster (born 25 September 1993) is an English professional rugby league footballer who last played as a second-row, loose forward or centre for Sheffield Eagles in the RFL Championship.
 He has previously played for the Leeds Rhinos in the Super League, and on loan from Leeds at the Hunslet Hawks, London Broncos and Featherstone Rovers. He played one season for the London Broncos in the Championship before returning to the Super League with the Castleford Tigers, where he spent the longest spell of his career. He appeared on dual registration from Castleford at Oxford and Halifax. He played for Newcastle Thunder in the Championship and was appointed club captain, before re-joining the Castleford Tigers on loan.
 Foster was born in Gloucester, Gloucestershire, England.
 Foster played junior rugby league for Wetherby Bulldogs before joining the Leeds Rhinos academy system.
 On 30 June 2013, Foster made his Super League début for the Leeds Rhinos against the Widnes Vikings. He scored his first Super League try against the London Broncos on 1 August, and made a total 8 appearances throughout the season. In November 2013, he signed a three-year deal with Leeds.
 In July 2013, Foster played one game for the Hunslet Hawks in the Championship on dual registration from Leeds.
 In January 2014, Foster signed a season-long loan deal with the London Broncos alongside fellow Rhinos youngsters Thomas Minns and James Duckworth. During the season, he played as a second-row or loose forward alongside Matt Cook and Mike McMeeken. Foster scored his first try for the Broncos against the Huddersfield Giants on 10 May. On 25 May, Foster scored two tries against Hull Kingston Rovers in a 48-16 defeat at Craven Park. He made 21 appearances in total, while London were relegated to the Championship.
 In November 2014, Featherstone Rovers announced the signing of Foster on a season-long loan for 2015, alongside three other young Leeds players. 
 After a spell with Featherstone Rovers, Foster signed for London on a two-year deal.[citation needed] Injury meant that he was restricted to 20 appearances for the Broncos.[citation needed]
 In 2017, Foster agreed a deal with Bradford however the club went into liquidation and Foster was released.
 In February 2017, Castleford head coach Daryl Powell confirmed that Foster had been offered a trial with the view of a two-year deal at the end of the trial. In April, it was confirmed Foster signed a deal until the end of the season with Cas (Heritage № 975) and was given the number 34 shirt. In July, it was confirmed that Foster had signed a new deal. On signing the new deal, he said, "I'm over the moon to sign here for another two years. It's a great place to be." Foster was a replacement for Cas in the 2017 Grand Final and scored their only try of the game, becoming the first Castleford player to score in a Super League Grand Final.
 Foster demonstrated his positional versatility in 2018, starting at loose forward, second row and centre at different points throughout the season. He was rewarded for his impressive form in June with a new three-and-a-half-year contract. However, in July, Foster was ruled out for the remainder of the season due to a foot injury.
 In the 2019 season, Foster made six appearances and scored one try. His playtime was limited by a knee injury sustained in March, for which he underwent surgery later in the year. 
 Foster made his return to the team following the 2020 season's Covid-19 suspension, after spending 16 months on the sidelines. In the remainder of the season, he made 8 appearances and scored 1 try.
 Foster sustained a bicep injury in a pre-season friendly against Hull KR in March 2021. He made his first appearance of the year in Castleford's Challenge Cup semi-final against Warrington on 5 June. On 17 July 2021, he played for Castleford in their 2021 Challenge Cup Final loss against St. Helens. In September, it was announced that he would leave the club at the end of the 2021 season upon the expiry of his contract. Speaking about his time at Castleford, Foster said, "It has been one hell of a journey and I am so thankful to everyone involved, from the coaching staff to the fans, my teammates as well who have made my time here what it has been for me."
 On 17 October 2021, it was reported that he had signed for Newcastle Thunder in the RFL Championship on a two-year deal. He made his first appearance and scored his first try for the club against Workington on 30 January.
 In July 2023, Castleford Tigers announced the return of Foster, signing on a season-long loan from Newcastle, alongside Greece international Billy Tsikrikas.
 On 14 November 2023 it was reported that he had signed for Sheffield Eagles in the RFL Championship on a two-year deal.
 (* denotes season still competing)