|Television Programs|| Unknown
|Video Games|| Finding Nemo: The Video Game
|Voice|| Albert Brooks (films)
Jess Harnell (game and attractions)
|Other names|| Marty
|Personality||Worrisome, fearful, kind, playful, caring, determined, brave, protective, fatherly, nervous, apprehensive, pessimistic, friendly, kind-hearted, intelligent, safety-conscious|
|Goal|| To find Nemo and reunite with him (Finding Nemo, succeeded)
To help Dory find her family (Finding Dory)
|Allies||His son Nemo, his wife Coral (disappeared), Bruce, Anchor, Chum, Dory, Whale, Crush, Nigel, Bailey, Destiny, Hank|
|Enemies||Darla, Dentist, Barracuda, Anglerfish, The Seagulls, Giant Squid|
|Likes||Staying safe, fun, being helped, making his son happy, having fun|
|Dislikes||Losing his son, Dory's singing, hurting others, being inside the whale, Dory speaking whale|
|Quotes|| "Dory, you did it!"
"You think you can do these things, but you just can't, Nemo!"
- ―Marlin comforting the egg of his last surviving child
Marlin is a clownfish who makes his home inside a sea anemone in the Great Barrier Reef. He once had a wife Coral who died in a barracuda attack, along with almost all of his children. Also as a result of the attack, he has one son, Nemo.
Marlin can be somewhat overprotective of Nemo. He also tends to be neurotic, worrisome and pessimistic believing Nemo can't swim well when he actually can swim pretty well for a fish with a small pectoral fin. However, this does not stop him from going on a journey to find his lost son, proving his determination.
Marlin was initially a very playful, happy, and easygoing clownfish as shown through the interaction with his wife. He was shown to be slightly lazy, as he wanted to name half of his children Marlin Jr. and the other half of his children Coral Jr. However, he was also shown to be very brave, as he attempted to defend his wife against the barracuda who sought to eat his children and his wife, but was ultimately repelled and knocked unconscious and into the sea anemone before he could do anything. This protected him, but also cost him his entire family, with the exception of Nemo, who was left with a crack in his egg, which could have caused his "lucky fin."
From this moment on, Marlin became overprotective, neurotic, paranoid, worrisome, and pessimistic, as he made several practices and conditions for Nemo and himself to follow to make sure they were protected and safe. He became paranoid and neurotic about any potential danger that could occur to Nemo and as such rarely left Nemo alone due to the traumatic experience of losing the rest of his family to a barracuda attack, and not wanting the same thing to happen to Nemo. However, this overprotectiveness is what put somewhat of a strain between him and Nemo, as Nemo felt suffocated and oppressed by it.
He also seems to, initially, be very serious, as shown when he couldn't tell a proper joke to some of Nemo's classmates' parents because he kept explaining obvious aspects of the joke, causing him to be considered unfunny despite the apparent notion that all clownfishes were supposed to be funny, which became a recurring gag throughout the movie as others state, "He's not very funny for a clownfish."
During his journey, Marlin was on the verge of losing Nemo, the only family he had left, and was rushing as fast as he could to save Nemo. This caused him to have little patience for Dory's antics and to other sidetracks.
However, despite these qualities, Marlin has proven to love his son more than anything and anyone in this world, and it is this love that fuels his determination, strength, courage, and bravery as he journeyed throughout the sea to find his son after he is kidnapped by humans. Marlin overcame with the bravery and courage not seen in his previous behavior to recover the person he loved most in the world despite the odds being against him.
Throughout the journey, he makes several friends and begins to understand that he should have given Nemo more freedom, particularly through his interactions with Dory and Crush because, as Dory states, "You can't let nothing happen to him, because then nothing will happen to him," meaning if Marlin doesn't let Nemo grow up and get out in the world, he won't be able to live life to the fullest.
He also begins to enjoy himself throughout his journey, and slowly sheds his serious personality, as shown when he had fun when he competed with Dory in racing to see who could get out of the jellyfish valley first and finally managed to have fun with his son Nemo by the end of the film.