India observes National Mathematics Day every year on December 22 to celebrate the life and work of Srinivasa Ramanujan, a great mathematician who was born on this day in 1887. The National Mathematics Day in India was announced in 2012 by then Prime Minister Manmohan Singh to mark the 125th birth anniversary of Srinivasa Ramanujan.

Indian men's hockey team beat Pakistan to win the bronze medal at the Asian Champions Trophy on December 22, 2021. The neck-to-neck contest ended with Manpreet Singh-led India beating arch-rivals 4-3 to secure third place in the tournament.

Australia's Marnus Labuschagne has become the new world no.1 batsman in ICC Men's Test Batsmen Rankings 2021, pushing England's Joe Root to the second spot. This is the first time that Labuschagne has taken up the top rank. He was earlier ranked at second place. 

India's highest-ranked test batsman in the ICC Test Player Rankings 2021 is Rohit Sharma, who is ranked 5th in the ICC Men's Test Batsmen Rankings 2021. Indian Test skipper Virat Kohli has slipped to the seventh spot from earlier sixth position.

Australian Test skipper Pat Cummins leads the ICC Test Men's Bowling Rankings. Ravichandran Ashwin is the only Indian bowler to feature in the top ten of ICC Test Bowler Rankings 2021. He has consistently maintained his second rank.

Sony Pictures Networks India Private Limited (SPNI) and Zee Entertainment Enterprises Ltd. (ZEEL) announced on December 21, 2021 that they have signed definitive merger agreements to combine their linear networks, digital assets, production operations and program libraries. Puneet Goenka will continue to remain as the MD and CEO of the merged new entity for a period of five years as part of the deal. 

PV Sindhu has been appointed as a member of the Badminton World Federation Athletes' Commission 2021-2025 along with five other players. The BWF announced the names of six new members of the commission on December 21, 2021. They include PV Sindhu, Zheng Si Wei (China), Iris Wang (USA), Robin Tabeling (NED), Kim Soyeong (KOR) and Greysia Polii (INA).

Delhi will get its first-ever Teachers University, as Arvind Kejriwal-led Delhi Cabinet approved a proposal to establish the university on December 21, 2021. The Chief Minister said that the University will be dedicated to preparing excellent quality Teachers across different school stages.