The players will be free to sign with any team come July 1.
King joined the Canadiens from the Los Angeles Kings via trade in March. The Meadow Lake, SK native appeared in 17 regular season games with Montreal, scoring one goal and registering 24 hits. He also appeared in all six games in the Canadiens' first-round series against the New York Rangers.
Flynn, 28, arrived in Montreal at the trade deadline in 2014-15. Since then, the native of Lynnfield, MA played 116 games with the Canadiens, scoring 10 goals and adding 10 assists.
The Canadiens acquired Nesterov in January from the Tampa Bay Lightning in exchange for defenseman Jonathan Racine and a sixth-round pick in 2017. The Russian blueliner played in 13 games with the Habs, registering one goal, four assists and a plus-3 rating to go along with 28 hits. Nesterov also suited up for two playoff games in 2017.