The fourth season of the American science fiction television series Star Trek: The Next Generation commenced airing in broadcast syndication in the United States on September 24, 1990 and concluded on June 17, 1991 after airing 26 episodes. Set in the 24th century, the series follows the adventures of the crew of the Starfleet starship Enterprise-D.

The third season of the American science fiction television series Star Trek: The Next Generation commenced airing in broadcast syndication in the United States on September 25, 1989 and concluded on June 18, 1990 after airing 26 episodes. Set in the 24th century, the series follows the adventures of the crew of the Starfleet starship Enterprise-D. This season featured the return of Gates McFadden as Dr. Beverly Crusher after she was replaced by Diana Muldaur for the second season. The season also saw the debut of several actors who would reappear in the same roles and others throughout the franchise, such as Dwight Schultz as Lt. Reginald Barclay, and Tony Todd as Kurn.