When not on professional duties, Lynn plays senior cricket for Toombul District Cricket Club in Brisbane.

Lynn played for the Queensland under-19 side and made his first-class debut as a 19-year-old against South Australia at the Gabba in March 2010. A week later, against Western Australia, he scored 139 runs in the second innings and effectively saved Queensland from defeat. He represents the Brisbane Heat in the Big Bash League. In his first season, he made 109 at an average of 21.80, in his second he made 175 at 35.00, including 51 off 29 balls against the Perth Scorchers and in his third he scored 198 runs at 28.28 with his best innings again coming against the Scorchers; this time he made 81.

He was a part of the Deccan Chargers team during the 2011 and 2012 Indian Premier League (IPL) tournaments but only got to play one match for the team in IPL 2012. He was bought by the Sunrisers Hyderabad for the 2013 competition but did not get the chance to play in a single match. For the 2014, season he was signed by the Kolkata Knight Riders and in his first game he was the man of the match, scoring 45 off 31 balls and taking a brilliant catch near the boundary to dismiss AB de Villiers and turn the game in the final over. In IPL 2015, he was retained by the Kolkata Knight Riders but he got injured and was ruled out of the tournament. Johan Botha came in as a replacement.

On 9 February 2015, he scored an unbeaten 250 against Victoria, in the Sheffield Shield.

On 29 December 2015, scored his first T20 century. Playing for Brisbane Heat in the Big Bash League hit 101 off 51 deliveries against the Hobart Hurricanes. He hit a career best 19-ball 50 as opener of Kolkata Knight Riders vs Gujarat Lions in IPL 2017 in which he hit 8 sixes. In the following match against the Mumbai Indians, he injured his shoulder while attempting to take a tough catch of Jos Buttler. He returned 1 month later and smashed a 22 ball 50 in his comeback match against Royal Challengers Bangalore, where he and Sunil Narine (54 off 17) smashed 105 runs in the 6 powerplay overs, which is a record. He continued his good form by scoring 84 in the next match, although unfortunately in a losing cause. He finished the season with a staggering strike rate of over 180, and despite missing most of the season, was one of the most impo