[5] He started for Munster A in their 31–12 2011–12 British and Irish Cup Final win against Cross Keys on 27 April 2012.
[6] On 28 February 2014, it was announced that Williams had signed a new one-year contract with Munster, which would see him remain in the province until at least June 2015.
[10] On 1 April 2017, Williams was a late replacement for the injured Conor Murray in Munster's line-up for the 2016–17 European Rugby Champions Cup quarter-final against Toulouse.
[15] After his release by Munster, Williams continued playing rugby at an amateur level for Cork Constitution.
He had decided to retire from playing rugby after Con's All-Ireland League Division 1A final against Clontarf in May 2019,[16] but after Con won the final 28–13 to secure their second AIL title in three years,[17] Williams extended his playing career into the 2019–20 season, and he started in the 24–17 win against Young Munster in the final of the Munster Senior Cup in December 2019, a victory that secured a 30th title for the Cork side.