John de Lancie
From Tardis Wiki, the free Doctor Who reference
John de Lancie played Allen Shapiro in the Torchwood stories End of the Road, The Gathering and The Blood Line.
He is probably best known for his recurring role as Q in Star Trek: The Next Generation, Star Trek: Deep Space Nine and Star Trek: Voyager from 1987 to 2001. He is also known for voicing the Q-like Discord in My Little Pony: Friendship is Magic from 2011 onwards.