Star Trek actors who have played John F. Kennedy: Cliff DeYoung (from DS9: "Vortex"): Robert Kennedy & His Times (1985) Andrew J. Robinson: Twilight Zone revival episode "Profile in Silver" (1986) Robert Pine (VGR/ENT guest and Chris Pine's father): TV movie Hoover vs. the Kennedys: The Second Civil War (1987) Steven Weber (from DS9: "The Siege"): The Kennedys of Massachusetts (1990) Stephen Collins: Miniseries A Woman Named Jackie (1991) Bruce Greenwood: Thirteen Days (2000) Steven Culp: Perception episode "Shadow" (2012) I could also add noted Shatner impersonator Maurice LaMarche, who did a voice in a Trek video game and also voiced JFK on Animaniacs. It's worth noting that both The West Wing's president and vice president, Martin Sheen and Tim Matheson, have played JFK. Also both cinematic Uncle Bens, Cliff Robertson and Sheen. While William Devane, who played JFK in The Missiles of October, has also played the US President in Stargate SG-1 and The Dark Knight Rises.
I never really cared for "Profile in Silver" that much, largely since I thought that Robinson (who was, of course, not well-known to me yet) was very poorly cast as JFK.
^ Bruce plays an awesome JFK in that one. And Steven Culp owns the role of RFK. Go ahead and try to spot all the Trek actors in it (there are lots). Poorly? I thought he was great.
I'm not disparaging Robinson's acting in the role -- he just didn't bear much resemblance to JFK, facially or vocally.
^ Sometimes it's not as important that they completely resemble the person they're portraying (Anthony Hopkins looked nothing like Nixon, and James Woods didn't much look like Rudy Giuliani either). As for Robinson: He and Lane Smith nailed the upper class New England accent to a T. That's not an easy accent to imitate. RIP Lane Smith, by the way.
I think it took Robinson a long time to "shake" his portrayal of the psycho killer in the first Dirty Harry movie. I remember seeing him once on a episode of Marcus Welby saying "Is my wife going to be all right?" and thinking, "I hope she dies."
Dare I admit that I only just tonight realized that Kirk's mom in the new movie is "Emma" from ONCE UPON A TIME . . . ? Which means that James T. Kirk is Thor's son and Snow White's grand-son!
Anyone already mentioned William Shatner's absolutely awesome guest appearance in seaQuest DSV? He's playing a ruthless Eastern European dictator who wants to train an army of dolphins to rule the world. And he has some Sybok-ish motivation. And he just hammers all his Shatnerisms in. And every time he makes a dramatic entrance, the first few notes of the Trek theme are played. Ab. So. Lute. Ly. Hi. La. Ri. Us.