Waller played through the Somerset Age Groups whilst he was a pupil at Millfield School, where he had a successful career, ending up as Captain of the 1st XI.

2017 saw Waller continue his run in white ball cricket, taking 16 wickets in the NatWest T20 Blast, including a career best of 3 for 37, as well as displaying amazing athleticism in the field.

[1] Somerset qualified for the T20 Blast finals day in 2018, with Waller taking 16 wickets in 16 games with an impressive economy rate of 6.78 runs per over.

[2] Waller also claimed his 100th wicket for the club in T20 cricket and becomes only the second person to achieve this feat after Alfonso Thomas.

[3] In February 2019, Waller was signed by Pakistan Super League side Quetta Gladiators as cover for the injured Sunil Narine.