A right-arm off-break bowler, Cornwall has played for Leeward Islands cricket team and featured in the line-up for the Antigua Hawksbills in the Caribbean Premier League.

[10] In a Regional Four Day Competition game versus Guyana in April 2017, he captained the Leeward Islands in the absence of Kieran Powell, who had been recalled to the West Indies Test side.

[13] In a disappointing season for the team, Cornwall was one of the more promising members of the squad; he finished the tournament with the second-best batting average in the side, as well being one of its more economical bowlers.

[14] His best performance came in a loss to the Barbados Tridents; having been promoted up the order to open, Cornwall reached his 50 off 26 balls (his first in T20 cricket), giving the Stars hope of chasing their target of 196.

[17] He was then the top wicket-taker in the 2018–19 Regional Four Day competition, taking 54 wickets, despite only playing nine matches;[18] these performances helped his team to 3rd place in the table.

However, a controversial declaration by Cornwall, who was stand-in captain for the last game of the season, in an attempt to stop their opponents, Barbados, from finishing second, backfired spectacularly.