It really was the perfect teen show, giving us plenty of drama while making us seriously jealous of the wealthy California lifestyle, and we can't quite believe it's been 15 years since we first met Ryan, Marissa, Summer and Seth.
The first episode aired on August 5th 2003 and it's fair to say many teens at the time were OBSESSED with the programme's theme tune.
And for a real throwback, here's the full tune!
Cover image via @theoc.official/Instagram