The TV host, 44, found fame in the UK as an actor thanks to family favourites including Gavin and Stacey and Fat Friends before landing his own talk show in the US.
However, his quest to make it to Hollywood could have taken a completely different turn had Peter Jackson taken a chance on the then-up-and-comer back in the late 90s.
Speaking on the Happy Sad Confused podcast, Corden opened up to host Josh Horowitz about the role that never was.
Watch: Ricky Gervais thought James Corden using his joke 'was absurd'
When asked if the rumour was true, Corden confirmed he had, tried to land a spot in Middle-earth and said: "[The audition was] Not good. Every single person in London auditioned for Lord of the Rings. Everybody! I auditioned for Samwise and I was sort of, I was doing it, Josh! I was doing the accent and everything."
Giving his rendition of the West Country accent Samwise has in the franchise, Corden revealed that actually got past the first stage of the audition process.
He explained: "Two of my other friends went in, and then we all got called back the next day, and then we got called back the next day… and then none of us got called back after that!"
The role eventually went to actor Sean Astin, with Lord Of The Rings creating a legacy that now including a prequel series Lord Of The Rings: Rings Of Power.
Rings Of Power has been renewed for a second season, expected in 2024.
Astin, who first found fame in the 1980s in The Goonies, has become a cult hero, appearing in shows including Stranger Things, The Big Bang Theory and 24.
Corden has confirmed he will be leaving The Late Late Show at the end of summer 2023, ending an eight-year tenancy of the series.
It's believed he's planning to move his family back to the UK, after living in Los Angeles throughout this period.