Jack Frank Porteous Cork (born 25 June 1989) is an English professional footballer who last played as a defensive midfielder for and captained EFL Championship club Burnley.

Cork started off his career with Chelsea but between 2006 and 2011, he went on loan to a number of clubs, including Scunthorpe United where he was named player of the year.

[14] He scored his first goal for Watford on 24 January 2009 in a 4–3 victory over Crystal Palace in the fourth round of the FA Cup.

[15] Cork signed a new three-year contract with Chelsea on 21 August 2009 and immediately joined Championship club Coventry City on loan until the end of December 2009.

[21] His father revealed the day before in a local newspaper, the Lancashire Telegraph, that Cork was looking to leave Chelsea in the summer and was willing to drop down into the Championship in order to do so.

[24] Cork scored a last minute winner at home to Derby County on 27 November, taking Burnley into the play-off positions.

[25] On 7 July 2011, Cork signed for newly promoted Championship club Southampton, after they agreed an undisclosed fee with Chelsea.

[33] Cork signed for Southampton's Premier League rivals Swansea City on 30 January 2015 on a three-and-a-half-year contract,[34] for a fee "believed to be in the region of £3 million".

[42] On 16 August 2018, he scored the winning goal in Burnley's 1–0 victory over İstanbul Başakşehir in the Europa League qualifiers.

On his role as a player/coach at the youth levels, he noted, "I’m not sure how fit I’ll be but maybe when the fixtures pile up ... maybe for 15 minutes or so, I can come on and play certain parts of the game to help that player see how someone with my experience would be able to cope in that role.”[46] Cork has represented England at many youth levels, making his under-19 debut against the Czech Republic in May 2007.

[51] He made his debut on 20 July in a 2–0 loss to Brazil in a pre-tournament friendly, coming on at half-time to replace Daniel Sturridge.