T1

The team that would become T1 was originally founded in 2002 by StarCraft player Lim "BoxeR" Yo-hwan under the name Team Orion, which was later renamed to 4 Union in December 2003. On April 13, 2004, South Korean wireless carrier SK Telecom sponsored the team with an investment of US$2 million, officially creating the team SK Telecom T1; by May 2005, it was estimated to have earned $15 million worth of market effects.

On December 13, 2012, SK Telecom expanded into League of Legends esports by acquiring the roster of Eat Sleep Game, and created the team SK Telecom T1 S. On February 26, 2013, they created a second League of Legends team, SK Telecom T1 K.

In 2016, SKT closed their StarCraft II division, after KeSPA announced that they would be discontinuing the Proleague.

In 2018, SK Telecom T1 expanded into two more esports, establishing a Hearthstone division on July 29 and a PlayerUnknown's Battlegrounds division on August 13. By 2019, SKT T1 had expanded to own and operate teams in at least eight games, including the two aforementioned, League of Legends, Fortnite, Dota 2, Super Smash Bros., and Apex Legends.

In October 2019, SK Telecom T1 was rebranded to simply T1, after SK Telecom and Comcast Spectacor partnered to create T1 Entertainment & Sports, and Joe Marsh was named the CEO. League of Legends player Lee "Faker" Sang-hyeok then became a part-owner of T1 Entertainment & Sports in February 2020.

On March 9, 2020, T1 signed its first player to its newly formed Valorant team.

On May 6, 2024, the Esports World Cup Foundation, funded by the Saudi Arabia Public Investment Fund and organizers of the Esports World Cup tournament series, announced the 30 organizations that would make up the World Cup Club Support Program, with T1 being one of them. This program gives teams a one-time six-figure stipend if an organization is willing to enter new esports as well as additional funding each year if they drive viewership and fan engagement to the Esports World Cup.