A clown fish named Marlin lives in the Great Barrier Reef loses his son, Nemo. After he ventures into the open sea, despite his father’s constant warnings about many of the ocean’s dangers. Nemo is abducted by a boat and netted up and sent to a dentist’s office in Sydney. So, while Marlin ventures off to try to retrieve Nemo, Marlin meets a fish named Dory, a blue tang suffering from short-term memory loss. The companions travel a great distance, encountering various dangerous sea creatures such as sharks, anglerfish and jellyfish, in order to rescue Nemo from the dentist’s office, which is situated by Sydney Harbor. While the two are doing this, Nemo and the other sea animals in the dentist’s fish tank plot a way to return to Sydney Harbor to live their lives free again.
在澳洲大堡礁的深海中，小丑鱼爸爸玛林和儿子尼莫简单幸福的生活着，可是爸爸做事常常畏首畏尾，是个胆小鬼，尼莫觉得爸爸很不勇敢，甚至有点看不起自己的爸爸。小尼莫却天不怕地不怕，跟同伴们去水面玩耍的时候，竟然被渔网捞了起来，辗转被卖到一家牙医诊所。玛林对儿子的生死未卜感到十分的担忧，就算平时不能大胆行事，为了儿子也要勇敢豁出去了。可是在路上遇到了很多艰难与恐惧，令他十分胆怯。幸好他遇到了好心的多瑞，一路与他作伴。父子俩都遇到了很多热心的帮助，最终都能重逢，玛林也从此成为儿子以及大家心中的英雄。