Mark Justin Roiland (born February 21, 1980) is an American voice actor, animator, writer, and producer. He co-created the Adult Swim animated sitcom Rick and Morty, for which he voiced the protagonists Rick Sanchez and Morty Smith from 2013 to 2022, as well as Hulu's Solar Opposites, in which he voiced main character Korvo from 2020 to 2022, until both networks severed ties with him in 2023. He had also voiced Earl of Lemongrab in Adventure Time, Blendin Blandin in Gravity Falls, and Oscar in Fish Hooks. He founded the animation studio Justin Roiland's Solo Vanity Card Productions! and the video game studio Squanch Games, though he resigned from the latter in 2023.

In early 2023, Roiland was dismissed from most of the companies he was working with due to accusations of domestic violence and abuse. The charges were later dismissed due to insufficient evidence, but in September 2023, new allegations of sexual assault were reported against him.