Director
Leonard Nimoy
You know that weird dude with the pointy ears? Spock doesn't just play a leading role in The Voyage Home—he also directed it.
We're talking, of course, about the late, great Leonard Nimoy. In the '70s, Nimoy started his directorial career in television, but he broke into the picture biz with 1984's Star Trek III: The Search for Spock. While The Search for Spock wasn't terribly successful, the film's producers were pleased enough with Nimoy's work to let him helm the next film.
Nimoy was more heavily involved with The Voyage Home than The Search for Spock. For example, he wrote the basic story, with Harve Bennett, and he was the leading voice behind the film's environmental message. Nimoy didn't exactly reinvent the wheel with his directorial approach, but he excelled nonetheless.
This would be Nimoy's final foray into sci-fi. He would direct three more films in his career, all of which were either family dramas or lighthearted comedies. Of these films, 1987's Three Men and a Baby would be his biggest success, boasting the top box-office gross of the year.
Frankly, we're still waiting for the Star Trek/Three Men and a Baby crossover. Fingers crossed.