 On 1 July 2018, Plekanec returned to the Canadiens, signing a one-year, $2.25 million contract.On 15 October 2018, Plekanec played in his 1,000th regular season NHL game, where he scored his first goal of the season.On 9 November 2018, the Canadiens announced that they would be placing Plekanec on unconditional waivers for the purpose of terminating his contact.