First-team breakthrough (2012–14)

Overton made his first-team debut for Somerset in the 2012 County Championship against Lancashire. He played seven County Championship games in 2012, taking 12 wickets at an average of 30.25. He also scored 75 runs at 10.71; scoring his maiden first-class half-century in the process. Overton also made his List A debut in this year, playing two forty over games.

Overton was unable to play throughout much of the 2013 season due to a stress fracture of the back. He managed to play a single first-class match in which he took just a single wicket.

The 2014 season saw Overton become a regular selection for the first-team as he played 27 matches across all three formats. His batting greatly improved as he scored 431 runs in the county championship in which he averaged 30.78 while also taking 42 wickets at 28.52. In a game against Lancashire, Overton fell short of making his maiden first-class century; given out while on 99. Making his debut in the twenty20 format, Overton struggled with both bat and ball taking just four wickets and scoring a total of 35 runs from 10 matches.

2015 season

In 2015, Overton was the leading wicket-taker for Somerset in both the County Championship and the One Day Cup taking 47 and 12 wickets respectively. He continued his batting form in the longer form of the game as he averaged 28.38 in 16 County Championship innings.

During a County Championship match against Sussex in September 2015, Overton abused Pakistani batsman Ashar Zaidi whilst bowling. He received a two match ban as a result of the incident. Zaidi later called on Overton to apologise for the abuse.^[15]

2016 season

Overton enjoyed another successful season in 2016 as he again made over 400 runs and took 34 wickets in the County Championship.^[16] During a Championship game against Hampshire, Overton made his maiden first-class century, scoring 138 as part of a stand of 217 for the eighth wicket with Roelof van der Merwe. This set a new record for the eighth wicket for Somerset, beating the previous record of 172 made by Ian Botham and Viv Richards in 1983,^[17] although the record was surpassed by Peter Trego and Ryan Davies in Somerset's next game.^[18]

Overton first played international cricket for England Under-19s playing a total of 16 youth ODIs between 2011 and 2012. He scored a total of 350 runs at an average of 26.92 with a high score of 68* as well as taking 14 wickets at 35.57.^[19]

Overton received his first international call-up in June 2015 when he was selected as cove