A product of the Fir Park youth system, Lawless was given a two-year professional contract in summer 2010, after helping Motherwell under-19's finish second in the 2009–10 Scottish Premier under-19 League, with Motherwell scoring the highest number of goals that season. Lawless was loaned to Annan Athletic for a month at the beginning of the 2010–11 season, only managing to appear twice in cup competitions. He was then loaned to Albion Rovers towards the end of the transfer window, along with Steven Meechan and Peter Innes. Initially the loan was to last six months, but was extended to a full season after Lawless had impressed. He scored his first goal, in a 2–2 draw against former club Annan Athletic on 19 February 2011. Between 16 April 2011 and 23 April 2011, Lawless scored back-to-back goals against East Stirlingshire and Queen's Park. Later in the season, he helped the Cliftonhill side to promotion to the Second Division, beating former club Annan Athletic in the play-off final. Lawless then returned to Fir Park and featured in a host of pre-season friendlies. He made his competitive first-team debut for Motherwell against Clyde in the League Cup, scoring the final goal in a 4–0 win. On 18 October 2011, Lawless returned to Albion Rovers on an initial 28-day emergency loan, scoring on his second debut for the club in a 2–1 loss to Dumbarton. He then scored a brace, in a 3–3 draw against Cowdenbeath on 3 December 2011. The loan was later extended until 5 January. On 11 May 2012, it was confirmed that Lawless would be released at the end of his contract, having not played regularly during the 2011–12 season. Since leaving Motherwell for Partick Thistle, Lawless has revealed he's disappointed to have never been given a chance in the first team at Motherwell.
Partick Thistle
Three days later on 15 May 2012, Lawless was signed by Jackie McNamara to play for Scottish First Division Partick Thistle by signing a two-year contract. Lawless scored his first goal (and the club's first goal of the season, with a left-footed shot, as Thistle beat Falkirk 3–1 in the opening game of the season and would score again, the following week, in a 1–0 win over Dunfermline Athletic. Having make a perfect start to the season, Lawless was awarded the August IRN-BRU SFL Phenomenal Young Player of the Month. Lawless would say he couldn't have asked for a better start in his Partrick Thistle's career. On 19 January 2013, during a match between Thistle and Falkirk, he provided an assist for Conrad Balatoni to score the first goal before coming off in the 25th minute with a fractured cheekbone and after going under the knife, he was set to be out for a month. However, Lawless made a quick recovery following the operation In his first season, Lawless become a regular player in the first team, scoring thirteen goals, including scoring three braces and he also helped Partick Thistle gain promotion to the Scottish Premier Leaguefor the first time in nine years. His performance not only attracted interest in Scotland, but also England. On 21 June 2013, Partick Thistle rejected a five-figure sum transfer fee for Lawless from recently relegated Dutch club Willem ll. In the 2013–14 season, Lawless played his first Scottish Premiership game, in a 0–0 draw against Dundee United, where he made his first start and played 90 minutes. Then, eight days later, he scored twice, in a 3–1 win over Ross County, giving Thistle their first win of the season and the first in the top flight since 2004. However, Lawless struggled for match action during the season. He then scored his third goal of the season, in a 5–1 loss against Motherwell on 29 December 2013 and then another against Ross County. Following a relatively successful season with Thistle in the Scottish Premiership, Lawless signed a further contract to keep him at Firhill until the end of the 2014–15 Scottish Premiership season. Lawless made his 100th overall appearance for the Jags in a 5–0 win over Hamilton Academical at Firhill on 21 January 2015. On 14 May 2015, Lawless was accused of breaching Scottish Football Association rules concerning gambling on matches and one week later was given a six-match ban, with four of those suspended until the end of the 2015–16 season. On 29 May 2015, he signed a new one-year contract extension with the Jags, keeping him at Firhill until the end of the 2015–16 Scottish Premiership season. Thistle were relegated to the Scottish Championship via the play-offs at the end of the 2017–18 season. Following that relegation, Lawless was one of many players released by the club.
