On 14 June 2016, after a successful short-term deal with the club, Hammill signed a 2-year contract with the club that will run to the summer of 2018. Upon signing a contract, Hammill revealed he turned down a move to Bristol City, citing family reason. Hammill started well at the start of the season, with Barnsley started well in a good form and scored his first goal of the season, in a 4–0 win over Rotherham United on 27 August 2016, and scoring again three weeks later on 13 September 2016, in a 4–0 win over Wolves.