Heart of Midlothian Wallace signed professional terms with
Heart of Midlothian in July 2004, having progressed from the club's youth team. Wallace made his debut in the
2004–05 season He was not selected in the match squad for the
2006 Scottish Cup Final. In the summer of 2006 fellow
Scottish Premier League club
Dundee United had a loan bid for Wallace rejected. A month later, Wallace signed a five-year contract with Hearts. Wallace was made Hearts vice-captain at the start of the
2010–11 season, however, a month later while representing Scotland in a
Euro 2012 qualifier against
Liechtenstein, he suffered a
cruciate ligament injury following a late challenge by
Martin Stocklasa. A week later
Rangers made an improved offer of £1m, which was also rejected. Hearts then placed a £3m price tag on Wallace.
Wolverhampton Wanderers, then a
Premier League side, had also expressed an interest in Wallace but did not make any offers. On 21 July 2011, a bid of £1.5m from Rangers was accepted by Hearts. Wallace signed a five-year deal with the club, becoming
Ally McCoist's second signing of the summer. Wallace scored his first goal for Rangers on Christmas Eve 2011 in a 2–1 defeat to
St Mirren. Four days later he thought he had scored again on his
Old Firm debut, but the goal was not given as it judged not to have crossed the line. Wallace scored his second goal for the club on 25 March 2012, against Old Firm rivals
Celtic, it was the third goal in a 3–2 win for Rangers. in 2013 Following the
liquidation of The Rangers Football Club plc, Wallace opted to transfer his contract to the new company. At the beginning of the 2012–13 season Wallace was appointed vice-captain. On 14 September 2012, Wallace signed a new five-year contract with Rangers. Wallace was sent off during a game against
Annan on 18 December 2012, conceding a penalty which was saved by Rangers goalkeeper
Neil Alexander. This red card was rescinded on appeal. Wallace started the first game of the 2013–14 season in a 4–0 win over
Albion Rovers in the
Scottish Challenge Cup. Wallace played in the first league game of the season in a 4–1 win over
Brechin City at
Ibrox. Wallace was the subject of much transfer speculation and both
Nottingham Forest and
West Ham United have been credited with interest in him. Forest manager
Billy Davies made a pair of cash bids for Wallace in a bid to take him to
The City Ground in January 2014, but each approach was turned down by the then Rangers chief executive Graham Wallace as the offers did not match the clubs valuation. On 21 July 2015, Wallace assumed the captaincy following the departure of previous captain
Lee McCulloch. He was later named club captain by new
Rangers manager
Mark Warburton on 16 August. Wallace opened the 2015–16 season campaign by scoring a brace in Rangers' 3–1 home victory over
St Mirren on 7 August 2015. Wallace was officially appointed captain on a permanent basis prior to Rangers' 5–1 win over
Alloa Athletic at
Recreation Park on 16 August 2015. On 5 April 2016, Wallace captained
Rangers to a 1–0 home victory against
Dumbarton to win the
Scottish Championship and earn promotion to the top flight of Scottish football. He also led out the team in the
2016 Scottish Cup Final, the first major final in five years for Rangers. The match ended in a 3–2 win for opponents
Hibernian, whose supporters staged a
pitch invasion at the final whistle; some Rangers players were confronted in the process of leaving the field, with Wallace a particular target due to his association with their
Edinburgh derby rivals Hearts, and he appeared to be struck by at least one person during the disturbance. On 20 June 2016, Wallace signed a contract extension with Rangers until 2019. After signing, Wallace stated that he wanted to finish his career at Rangers. Wallace missed a
2016–17 Scottish League Cup match against
Peterhead on 9 August 2016, which ended a run of consecutive competitive appearances at 69 that had begun in February 2015. In September 2017, Wallace sustained a double
hernia injury during a match against
Partick Thistle. Initially ruled out for a few months, he did not play again in the 2017–18 season. After an internal investigation Wallace was fined four weeks' wages by Rangers, the maximum amount permitted. Wallace returned to the Rangers squad for pre-season activities in June 2018. At the outset of the campaign, he was replaced as club captain by
James Tavernier. In early September, he was not included in the Rangers squad for the
2018–19 UEFA Europa League group stage; two days later, it was announced that he and Kenny Miller had won an appeal at a SPFL tribunal against the disciplinary action taken against them five months earlier, with the expectation they would make a financial claim against the club for the fines imposed. He would go on to make three substitute appearances in the 2018–19 season, getting a great reception from the Rangers supporters.
Queens Park Rangers On 14 June 2019, Wallace joined
English Championship team
Queens Park Rangers on a two-year deal upon the expiry of his Rangers contract. Wallace made his debut in a 2–0 loss against
Leeds United where he played as a left-side centre-back. He scored his first goal for QPR on 5 January 2020 in the
FA Cup against
Swansea City. On 6 March 2021, Wallace captained his first QPR game in a 2–0 win against
Bristol City due to the absence of
Geoff Cameron and captained 9 games after that. On 15 May 2021, Wallace agreed a new one-year contract keeping him at QPR until 2022. ==International career==