He is best known for collaborating with former SpongeBob writer C.H. Greenblatt, to serve as creative director on his cartoon Chowder.
They later worked as directors for Fish Hooks, which he co-developed with Alex Hirsch and Noah Z. Jones for Disney Channel. After Fish Hooks, he worked on Mickey Mouse as a writer, storyboard artist and director.
In 2016, Reiss worked on C.H. Greenblatt's series for Nickelodeon, Harvey Beaks.
Trivia
As revealed in the season 2 DVD audio commentaries, he is called Bill by his friends.
According to the DVD audio commentary for "Big Pink Loser," that episode was the first episode he had written for any cartoon.
In "I'm Your Biggest Fanatic," he is credited as Williams Reiss, but back to William Reiss without one of the "S" in the "written by" section of the credits.