He has had a number of different partners, but primarily played alongside his British compatriots, most notably Ross Hutchins, Jamie and Andy Murray, Ken Skupski and Jonathan Marray.

The university offered him the opportunity to continue with his tennis training and competition as part of a high quality programme, otherwise he would have become a social player at that time.

[22] Ken Skupski finished the year there because he'd had a long year, but Fleming continued by partnering Jonny Marray in the Czech Republic and winning two Futures in Frydland Nad Ostravici,[23] and Opava[24] In February, the Davis Cup captain John Lloyd decided to hold play-offs between six British tennis hopefuls to determine the players for the next tie.

[26] In March, Fleming, ranked 289, made his debut in Great Britain's Davis Cup team for their Europe/Africa Zone Group I match against Ukraine in Renfrewshire.

[32] In January Fleming competed in his first grand slam outside of Wimbledon at the Australian open again partnering Ken Skupski made it to the second round.

In March, Fleming and Skupski were called to the Davis Cup team in the Europe/Africa Zone Group II tie vs Lithuania, in Vilnius, with James Ward, and Dan Evans.

[4] Fleming and Ross Hutchins agreed to begin next year as steady partners, and in November they had a winning start at the Kazakhstan Challenger.

[41][42] A week later, Fleming and Scott Lipsky won the Status Athens Open Challenger final because their opponents Matthias Bachinger and Benjamin Becker withdrew.

[44] At Wimbledon, Fleming and Ross Hutchins both had their best performances at a Grand Slam event in doubles, defeating 7th seeds Mariusz Fyrstenberg and Marcin Matkowski in the first round.

Fleming and Hutchins won their first-ever five-set match together over Dmitry Tursunov and Grigor Dimitrov in the second round,[45] on the way to the quarter-finals, where the pair lost a very tight five set thriller to Christopher Kas and Alexander Peya 4–6, 4–6, 7–6(7–2), 6–2, 4–6.

[39] It was announced on the morning of the quarter-finals that Fleming had been picked alongside Jamie Murray for the doubles rubber for Britain's Davis Cup tie against Luxembourg in two weekends' time, leaving Hutchins on the sidelines.

Then in September, at the Davis Cup, Fleming helped Great Britain win their promotion tie 5–0 against Hungary to advance to Group I playing in both the doubles, partnered by Ross Hutchins, and one of the dead singles rubbers.

James Ward's loss and Dan Evans' win put the tie at 1–1 on the first day, then Fleming and Hutchins beat Michal Mertiňák and Filip Polášek 6–3 7–6 (7/4) 0–6 6–3.

Fleming won his second title with Hutchins and his first in the 2012 season at the Delray Beach International Tennis Championships, defeating Michal Mertiňák and André Sá, 2–6, 7–6(7–5), [15–13].

After Josh Goodall and Dan Evans lost on the first day, Fleming and Hutchins made it three straight victories in the competition by beating Ruben Bemelmans and David Goffin 4–6, 7–5, 6–3, 6–4.

Fleming teamed up with fellow Scot Jamie Murray for the Australian Open, however they lost in the first round to Michael Kohlmann and Jarkko Nieminen.

Following a break of around two weeks, Fleming then teamed up with Wimbledon champion Jonathan Marray at the Open Sud de France where they were the top seeds.

At Indian Wells, Fleming teamed up with Paul Hanley of Australia, with whom he made it to the quarterfinals before losing to Bruno Soares and Alexander Peya.

After a first round defeat in the Miami Masters, partnered by Jonathan Marray, the two Brits returned to the UK for Great Britain's first Davis Cup fixture of the year.

En route to the final, the pair defeated Marray's former partner Frederik Nielsen, with whom he had won the Wimbledon doubles title the previous year.

The two made it to the third round, but they couldn't replicate the form that saw Marray clinch the title during the previous season, going out in straight sets to Daniel Nestor, and Robert Lindsteadt.

The pair made their second final of the year at the BB&T Atlanta Open, where they lost to the French-Dutch duo of Édouard Roger-Vasselin and Igor Sijsling.

As their ranking was too low to compete in the Rogers Cup, Fleming teamed up with fellow Scot and world number 2 singles player Andy Murray for the first time.

They pulled off a four set win against Ivan Dodig and Mate Pavić[69] to help beat Croatia 4–1, and return to the World Group for the first time since 2008.

Fleming and Inglot had not played a competitive match together since a junior tournament in Corfu 13 years ago, and so the world-beating Bryan brothers, posted a four-set win 6–2, 6–3, 3–6, 6–1 against FlemIng/Inglot.

[73] Later, Andy Murray secured his second singles victory; Great Britain winning the tie 3–1, to reach the Davis Cup quarter-finals for the first time since 1986.

In April, Fleming, Andy Murray, James Ward and Dan Evans were selected for the World Group quarter final against Italy, with Ross Hutchins as reserve.

Fleming/Hutchins struggled to find form throughout the year but managed to turn things round in May by reaching the final of the BMW Open,[75] where they were defeated by Jamie Murray and John Peers.

[76] Fleming then teamed up with Andre Sá to play the Aegon Trophy in early June, where they were narrowly defeated in the final by Chris Guccione and Rajeev Ram.

[81] Fleming then teamed up with Eric Butorac for the first time at the ATP World Tour Nottingham event in June, eventually losing the semi-final against Chris Guccione and André Sá 6–2, 2–6, 9–11.