Iroh is the leader of the White Lotus. He comes from the Fire Nation, and is known as the Dragon of the West. He is a caring and wise old man.
Jeong-Jeong is a Fire Nation Army deserter, and is Lotus Master of Fire. His firebending is only second to Iroh's, and seems to think of it as a curse at some points, and wishes he could be a waterbender. He ambushes and battles Nigel Uno in Dusty Desert.
Piandao is the Lotus Master of Swords, and is one of the few non-benders. While his position is meant to teach swordsmanship, he is also meant to be an example of how nonbenders can be just as strong as benders. He battles Rachel T. McKenzie outside the Tree of Beginning.
Wesley Dodds is a retired superhero, but appears to be a member of the White Lotus that watches over the KND's world. He has no element, but wields a poison gas gun. He and his partner, Larry Oldman, ambushed the Toxic Four in the Silver River Forest. He is primarily Nolan York's mentor.
Mewtwo is the Lotus Master of Psychic, and appears to be a member as hinted in Chapter 55 of Firstborn. He's trained Mikaela Corella for 6 years, and has trained The Quads in the ways of The Force on New Island.
Clockwork is the Lotus Master of Time, and appears to be a member as hinted in Chapter 55 of Firstborn. He is the only spirit being, excluding Mewtwo, and has trained Jagar King in the ways of timebending.
Most of the White Lotus members were retired or bested by their chosen students, who have then taken their place.
Annie is Vaati's assistant, who shares in his freedom ideology. She is an expert slingshot sniper.
Mika is the Logia Psychic Master who surpassed Mewtwo.
Rachel is the Sword Master who surpassed Piandao.
Angie is the Logia Earth Master who surpassed Bumi.