The 2021–22 T1 League season was the first season of the T1 League, with the Kaohsiung Aquas, the New Taipei CTBC DEA, the Taichung Wagor Suns, the Tainan TSG GhostHawks, the TaiwanBeer HeroBears, and the Taoyuan Leopards participating in this competition. The regular season started on November 27, 2021 and ended on May 20, 2022.^[2][3][4] The play-in series was played on May 22.^[4][5] The semifinals series started on May 24 and ended on May 28.^[4][6] The finals series started on May 31 and ended on June 4.^[4][7] On June 4, the Kaohsiung Aquas defeated the Taichung Wagor Suns, 3–0, winning the 2021–22 season championship.^[7]

• Each team plays against another six times, three at home and three on the road, respectively. Each team plays 30 matches total in the regular season.^[8]
• Play-in series: Best-of-three series. The series are contested by the teams that finished the regular season as the fourth seed and fifth seed. The fourth seed is awarded a one-win advantage. The winner can qualify to the semifinals series.^[9]
• Semifinals series: Best-of-five series. Matchup is decided by seeding in regular season. The first seed plays against the winner of play-in series. The second seed plays against the third seed. The winners can qualify for the finals series.^[9] Due to the COVID-19 pandemic in Taiwan, the semifinals series change to best-of-three series.^[4]
• Finals series: Best-of-seven series. The series are contested by the winners of semifinals series.^[9] Due to the COVID-19 pandemic in Taiwan, the finals series change to best-of-five series.^[4]

• Each team is able to register up to 4 general import players and 2 type-III players.^[10]
• Each team is able to select 3 general import players and 1 type-III player into active roster in each match.^[11]
• The maximum of import players on the court is two.^[11]
• 10-Imports-In-4-Quarters Rule : two quarters can have 2 import players and 1 type-III player on the court, and other two quarters can have 2 import players or 1 import player and 1 type-III player on the court.^[11]
• Type-III player eligibility:^[12]

(1) Naturalized players
(2) Asian import players[lower-alpha 3]
(3) Foreign students
(4) Overseas compatriots

The preseason started on November 13, 2021, and ended on November 14. The T1 League held the Kaohsiung Port pre-season matches at the Kaohsiung Arena.^[26]

The regular season started on November 27, 2021 and ended on May 20, 2022.^[2][3][4] On November 27, the 2021–22 season opening game, matched by the Kaohsiung Aquas and the TaiwanBeer HeroBears, was played at University of Taipei Tianmu Campus Gymnasium.^[27]

• Play-in series: The fourth and fifth seeds play the best-of-three play-in series. The fourth seed will be awarded a one-win advantage. The winner can qualify the semifinals series.^[9][4]
• Semifinals series: The winner of play-in series and the top three seeds play the best-of-five semifinals series. The winners can qualify the finals series.^[9] Due to the COVID-19 pandemic in Taiwan, the semifinals series change to best-of-three series.^[4]
• Finals series: The winners of the semifinals series play the best-of-seven finals series.^[9] Due to the COVID-19 pandemic in Taiwan, the finals series change to best-of-five series.^[4]

• The Kaohsiung Aquas announced that they would play their home games at the Kaohsiung Arena on May 26, 2021.^[50]
• The Taichung Suns announced that they would play their home games at the National Taiwan University of Sport Gymnasium on June 19, 2021.^[51]
• The New Taipei CTBC DEA announced that they would play their home games at the Xinzhuang Gymnasium, and would share the same arena with the New Taipei Kings of the P. League+ on September 4, 2021.^[52]
• The TaiwanBeer HeroBears announced that they would play their home games at the University of Taipei Tianmu Campus Gymnasium on September 16, 2021.^[53] And they scheduled two of their home games at the Taipei Heping Basketball Gymnasium.^[54]
• The Taoyuan Leopards announced that they would play their home games at the Chung Yuan Christian University Gymnasium.^[55]
• The Tainan TSG GhostHawks announced that they would play their home games at the Chia Nan University of Pharmacy and Science Shao Tsung Gymnasium on November 15, 2021.^[56]
• The Kaohsiung Aquas announced that they would play their home games in playoffs at the Fengshan Gymnasium on April 17, 2022.^[57]
• The Taoyuan Leopards announced that their home games on April 23 and 24, 2022 would change to Taipei Heping Basketball Gymnasium in Taipei City.^[58]
• The Taoyuan Leopards announced that their home games on May 18 to 20, 2022 would change to Taoyuan Arena.^[59]

• The games will be broadcast on television via Eleven Sports and ELTA TV, and online via 17LIVE.^[60]
• The games will be broadcast online via Twitch since 2022 and via Facebook since January 26.^[61][62]
• The games will be broadcast online via LINE TODAY since play-in series.^[63]

• On May 26, 2021, the Kaohsiung Aquas was established formally to be the new team of the T1 League.^[50]
• On June 19, 2021, the Taichung Suns was established formally to be the new team of the T1 League.^[51]
• On July 30, 2021, the New Taipei CTBC DEA was established formally to be the new team of the T1 League.^[17]
• On August 4, 2021, the first trade (between Kaohsiung Aquas and New Taipei CTBC DEA) was made in T1 League history.^[64]
• On August 6, the T1 League announced that Chien Wei-Chuan was the commissioner of the league.^[65]
• On August 6, 2021, the Taoyuan Leopards and the Tainan team were established formally to be the new teams of the T1 League.^[65]
• On August 9, 2021, the first draft was held in T1 League history.^[16]
• On August 27, 2021, Cheng Wei of the Taoyuan Leopards became the first player to join four Taiwanese related basketball league (SBL, ABL, PLG, and T1).^[66]
• On September 2, 2021, the TaiwanBeer HeroBears was established formally to be the new team of the T1 League.^[67]
• On September 6, 2021, the T1 League announced that Chang Yun-Chih was the secretary general of the league.^[68]
• On September 30, 2021, the name of Tainan team was announced as the Tainan TSG GhostHawks.^[69]
• On November 27, 2021, the game matched by the Kaohsiung Aquas and the TaiwanBeer HeroBears became the first game in T1 League history.^[27]
• On December 4, 2021, the game matched by the TaiwanBeer HeroBears and the New Taipei CTBC DEA became the first overtime game in T1 League history.^[70]
• On December 11, 2021, Tony Mitchell of the TaiwanBeer HeroBears became the first player to record triple-double (with 24 points, 11 rebounds, and 10 assists) in T1 League history.^[71]
• On December 26, 2021, Yu Huan-Ya of the Kaohsiung Aquas recorded 300 three pointers in his career.^[72]
• On February 13, 2022, Yu Chun-An of the Kaohsiung Aquas recorded 1000 points in his career.^[73]
• On March 16, 2022, Chou Tzu-Hua became the first player to involve the trade in T1 League history.^[74][75]
• On May 22, 2022, the game matched by the TaiwanBeer HeroBears and the Taoyuan Leopards became the first play-in game in T1 League history.^[76]
• On May 24, 2022, the game matched by the New Taipei CTBC DEA and the Taichung Wagor Suns became the first semifinals game in T1 League history.^[77]
• On May 31, 2022, the game matched by the Taichung Wagor Suns and the Kaohsiung Aquas became the first finals game in T1 League history.^[78]
• On June 4, 2022, the Kaohsiung Aquas became the first team to win the championship in T1 League history.^[7]

• 2021–22 Kaohsiung Aquas season
• 2021–22 New Taipei CTBC DEA season
• 2021–22 Taichung Wagor Suns season
• 2021–22 Tainan TSG GhostHawks season
• 2021–22 TaiwanBeer HeroBears season
• 2021–22 Taoyuan Leopards season