He graduated through the Wolverhampton Wanderers Academy to turn professional in February 2007. He spent much of the 2007–08 season on loan at Hereford United, helping the club to win promotion into League One. He joined Port Vale on loan at the start of the 2008–09 season, and his loan stay was made permanent in January 2009. He played 53 games for the club in 2009–10, and continued to be a key member of the defence in 2010–11. He joined Barnsley on loan in March 2012, with a view to a permanent deal in the summer. From Barnsley, he was loaned out to Shrewsbury Town in September 2012. He moved on to Northampton Town in February 2013, and spent over two years with the club before moving on to Mansfield Town. He signed with Forest Green Rovers in May 2017.
Born in Telford, Shropshire, Collins was promoted to Wolverhampton Wanderers' first team squad for the first time in January 2007, signing his first professional forms the next month. Though regularly on the bench, he never made a first team appearance. However, he played regularly for the club at reserve level and with the under-18s, for whom he was captain.
He joined Hereford United on 14 November 2007 on an initial month's loan, and made his league debut on 17 November 2007 in a 3–2 win at Stockport County. After impressing, his loan was extended to the end of the season, during which Hereford won promotion to League One.
Collins went on loan to League Two side Port Vale at the start of the 2008–09 season, and became a first team regular. Vale then signed him on a two-and-a-half year deal on 16 January 2009 after "Wolves" agreed to release him from the rest of his deal at Molineux. He gained his first senior goal in a 1–1 home draw with Wycombe Wanderers on 25 April 2009. With 42 appearances to his name in his first season with the club, he was described as the most consistent performer of the season.
He remained in the first team for the start of the 2009–10 campaign. He was transfer listed in late September, along with the entire Port Vale squad, after manager Micky Adams saw his team slip to a third consecutive defeat. Despite this he remained a key member of the defence, alongside Gareth Owen and John McCombe. Playing regular football helped Collins realize that he needed to 'bulk out' to become a more physically dominant player. His solid performances attracted attention, as well as March 2010 rumours of a £200,000 move to Watford. Rumours that Collins rubbished as "paper talk". A candidate for Player of the Year, he instead picked up Chairman's Player of the Year and Players' Player of the Year awards, as well as the award for Best Assist "following his storming run from inside his own half to set up Marc Richards against Hereford at Vale Park". Collins was keen to extend his contract beyond its conclusion in the summer of 2011.
He got the perfect start to the 2010–11 season by blasting in the only goal of the opening game of the season at Bury. Anticipating interest from other clubs, in September Adams began negotiations to extend his contract by a further season. Upon signing the deal Collins praised current and former training staff at the club, naming Dean Glover, Lee Sinnott, Mark Grew, Geoff Horsfield, and Micky Adams as people who helped his progress 'massively'. His consistency over his 48 appearances helped Vale to boast one of the strongest defensive records in the division that season.
He missed a few weeks at the start of the 2011–12 season after undergoing a small operation to repair a hernia-related problem. He was then sidelined for a further five weeks after he had to undergo surgery on an unrelated groin injury. Vale conceded eighteen goals in the twelve games that Collins missed, before keeping a clean sheet on his return to the first team on 12 November, a goalless draw with Grimsby Town in the FA Cup. He again was sidelined in January, as he picked up an ankle injury. In total he made 162 appearances for Vale, scoring four goals.
On 15 March 2012, Collins joined Barnsley on loan for the remainder of the season, with the move becoming permanent at the end of the season. Port Vale received £50,000 for the loan deal. He arrived at Oakwell in the midst of an injury crisis in the Barnsley defence. He impressed manager Keith Hill in his seven appearances in 2011–12, particularly in the game against Blackpool.
Despite injuries to other "Tykes" defenders, he did not feature in the first team at the start of the 2012–13 season. On 28 September 2012, Collins joined League One side Shrewsbury Town on a month-long loan deal. "Shrews" boss Graham Turner, his former manager at Hereford, said that he would provide valuable defensive experience and cover following an injury to Joe Jacobson. Collins made eight appearances before he had his loan deal extended by one month. On 29 November, his loan was cut short and he returned to his parent club. Having never taken to the field for Barnsley in the 2012–13 season, he was released from his contract on 31 January 2013 by manager David Flitcroft.
He joined Northampton Town until the end of the 2012–13 season in February 2013. Manager Aidy Boothroyd signed him to provide competition in the "Cobblers" defence, particularly to left-back Joe Widdowson. On 20 April, he scored an own goal at Vale Park which effectively promoted his former club, Port Vale, back into League One. He was allowed to participate in the play-offs, despite being subject to a curfew order. He played 55 minutes of the play-off final defeat to Bradford City. He signed a new two-year contract in May 2013.
He played 25 games during the 2013–14 campaign as Northampton avoided relegation out of the Football League by a three-point margin, though played only twice under new manager Chris Wilder after he was ruled out for the rest of the season with a foot tendon injury in February. During the season, he was appointed as club captain. He made 43 appearances in the 2014–15 campaign but was not offered a new contract in the summer as Wilder opted to use Zander Diamond and Ryan Cresswell as his new centre-back partnership.
Collins joined League Two club Mansfield Town in June 2015, with "Stags" manager Adam Murray praising his ability and experience, saying that "To bring Lee in to the building is a big one for us". He made 38 appearances across the 2015–16 campaign after recovering from a foot injury picked up in pre-season. He was appointed club captain in January and went on to sign a new contract in the summer. He was released by Mansfield at the end of the 2016–17 season, having made 44 appearances to help Mansfield to a 12th-place finish.
In May 2017, Collins joined Forest Green Rovers on a two-year contract to become the club's first signing following their promotion from the National League into the English Football League .
Collins was called up to the England under-19s, but did not earn a cap. Despite this he does not rule out one day playing for the Republic of Ireland, who he qualifies for through his Irish father.
Collins can play anywhere in defence, though prefers to play at centre-back. Port Vale manager Micky Adams claimed that Collins always gave his all in training, and was a "remarkable athlete... [in] terms of fitness." In February 2010, teammate Marc Richards said that "he reads the game well, he's fast, he's strong...[and has] strength and pace, and he's got vision as well."
Collins attended Thomas Telford School as a youth, alongside fellow professionals such as Elliott Bennett and Danny Guthrie. Also attending the school was future Port Vale teammate Sam Morsy. His partner Rachel gave birth to their daughters, Amelia, on 15 December 2010 and Laila-Rose on 14 March 2016.
Collins was convicted for assault in April 2013 after punching and kicking a man in Shropshire the previous year, and was given a two-year suspended prison sentence.As of 22 May 2017.
Hereford UnitedFootball League Two third place promotion: 2007–08