John Sherwood de Lancie, Jr. is an American actor, best known for his role as Q in various Star Trek series, beginning with Star Trek: The Next Generation in 1987 and leading up to the third season of Star Trek: Picard in 2023.

Q is a fictional character, as well as the name of a race, in Star Trek, appearing in the Next Generation, Deep Space Nine, Voyager, Lower Decks, and Picard series and in related media. The most familiar Q is portrayed by John de Lancie. He is an extra-dimensional being of unknown origin who possesses immeasurable power over time, space, the laws of physics, and reality itself, being capable of altering it to his whim. Despite his vast knowledge and experience spanning untold eons, he is not above practical jokes for his personal amusement, for a Machiavellian or manipulative purpose, or to prove a point. He is said to be almost completely omnipotent and he is continually evasive regarding his true motivations.