After his young son Nemo is captured in the Great Barrier Reef and taken to a Sydney dentist's office, it is up to Marlin, a single parent and the forgetful Dory to find a way to get Nemo home safely.
Dory, a Paracanthurus, gets separated from her parents as a child. As she grows up, Dory attempts to search for them, but gradually forgets them due to her short-term memory loss. In the flashback of the previous film, ''Finding Nemo'', she joins Marlin – a clownfish looking for his missing son Nemo – after accidentally swimming into him. Marlin decides to help Dory look for her long lost parents with the help of some unlikely friends they meet along the way.