Lee Sin's name is a homophone of the word "listen."
A rough translation of his name in Spanish is "no reading".
His self-immolation from the lore is a reference to the real life monk who publicly set himself on fire. He did this as an act of protest against the persecution of Buddhism in South Vietnam.
Lee Sin is the first champion to feature two champion spotlights, a real one and a fake one for April Fool's.
Lee Sin is the first champion to use energy that is not a ninja. Though, similar to the other ninjas, he is a champion that hails from Ionia.
Lee Sin shares a quote with Soraka, "Where am I needed?"
Lee Sin is one of only five champions to have more than 4 skills, the other being Nidalee, Jayce , Elise and Quinn.
Lee Sin is the first monk type champion announced but the second to be released after Udyr.
Lee Sin is the only allegedly cancelled Champion to be introduced to the game under his original name.
Lee Sin was a cancelled Champion that got brought back by community popularity and support.
Lee Sin's dance style is referenced to one of 'Mighty Steel Legs' moves in the movie Shaolin Soccer. A side-by-side comparison can be seen here.
Lee Sin is the first champion to be re-designed and to be given a re-launch skin in technicality as his classic skin was originally the Traditional Lee Sin skin, however the change occured before his release.
Lee Sin's voice actor is David Wenham. He is also the one that starts in Lord of The Rings as Faramir.
For April Fool's, the original Classic skin artwork used to have the deceased champion Urf, the Manatee, who could be seen at the bottom left of the artwork.
Traditional Lee Sin resembles how he looked before his official release (seen in the second official trailer). Click here.
He can be seen at around 0:11, between Jax and Teemo.
Acolyte Lee Sin was meant to show his appearance during his time as a summoner in training.
Dragon Fist Lee Sin (Lunar Revel 2012 event release) skin is a tribute to Bruce Lee, the famed martial artist/actor of 1970's action movies. The skin seems to be specifically referencing his trademark look first seen in Enter the Dragon.
Dragon Fist Lee Sin's idle animation is Bruce Lee's move when serious.
Muay Thai Lee Sin was created to celebrate the launch of League of Legends in Thailand and pays homage to Muay Thai, a combat sport native to the country.
Muay Thai Lee Sin is the third non-legendary skin to have a different dance animation from the original skin, prior being Jurrasic Cho'Gath and Dynasty Ahri. His dance is referenced from the movie "Ong Bak". A side-by-side comparison can be seen here .
Lee Sin was once a summoner-in-training at the League, before committing a devastating incident which left him with profound guilt. After the devastating incident, he traveled to the Shojin Monastery in Ionia in order to repent, becoming a brethren to the monks there.
Lee Sin's former mentor was High Councilor Reginald Ashram, the first leader of the League.
Lee Sin has a sister from the now liberated province of Galrin.
Lee Sin did an interview with L. B. Briskes on a raft over Lake Contemplation.