1977–78 Seattle SuperSonics season

The 1977–78 Seattle SuperSonics season was the 11th season of the franchise in the National Basketball Association (NBA).

With a disappointing 5–17 start, the Sonics replaced coach Bob Hopkins with future Hall of Famer Lenny Wilkens, who led the team to a 47–35 finish.

In the playoffs, the SuperSonics defeated the Los Angeles Lakers in three games in the First Round, then upset the defending NBA champions Portland Trail Blazers in six games in the Western Conference semifinals, before finally defeating the Denver Nuggets in six games in the conference finals, making their first trip to the NBA Finals in franchise history, where they lost the series to the Washington Bullets in 7 games.