Greg Morris played Barney Collier in the original 1966 Mission: Impossible
, and never appeared in Trek. His son Phil Morris played Barney's son Grant Collier in the 1988 M:I revival series. Phil Morris has made several appearances in Star Trek
, both before and after his M:I gig (not just after as I mistakenly said before). He was one of the Onlies in "Miri" (the one in an army helmet), Cadet Foster in The Search for Spock
(the guy who asked if there'd be a ceremony when they got home), a Klingon and a Jem'Hadar in DS9, and astronaut John Kelly in VGR: "One Small Step."