These shorts made by Pixar have been released in different ways: theatrically, or as bonus features on home media, or online. Some are related to Pixar's feature films, and some are standalone works.

22 vs Earth
Boundin'
Ciao Alberto
For the Birds
Geri's Game
Jack-Jack Attack
Knick Knack
Lamp Life
The Legend of Mor'du
Lifted
La Luna
Luxo Jr.
Mater and the Ghostlight
Mike's New Car
One Man Band
Tin Toy
Your Friend the Rat

series
Cars Toons
Toy Story Toons