List of 1978 Seattle Mariners draft picks

The following is a list of 1978 Seattle Mariners draft picks. The list includes the June regular draft (Rule 4 draft), the June secondary draft, and the January regular draft, and January secondary draft. In all of the drafts, the Mariners made 34 selections, including 12 pitchers, 6 catchers, 5 outfielders, 3 utility players, 3 shortstops, 2 first basemen, 1 infielder, 1 third baseman, and 1 second baseman. Six players drafted by the Mariners in 1978 went on to play in Major League Baseball.