List of Famous people who died at 21

Masataka Sugimoto is a Japanese professional shogi player ranked 8-dan. He is a former non-executive director of the Japan Shogi Association.

Mirko Šarić was an Argentine footballer who played as a midfielder.

Marcia Lenore Sossoman (King) was a 21-year-old Arkansas woman who was murdered in April 1981 and whose body was discovered in Troy, Ohio approximately 48 hours after her murder. Her body remained unidentified for 36 years before being identified via DNA analysis and genetic genealogy in April 2018. King was the first unidentified decedent to be identified via this method of forensic investigation.

Second Lieutenant Arun Khetarpal, PVC born in Pune, Maharashtra, was an officer of the Indian Army and a posthumous recipient of the Param Vir Chakra, India's highest military decoration for valour in face of the enemy. He was martyred in action in the Battle of Basantar in the Battlefield of Shakargarh during the Indo-Pakistan War of 1971 where his actions earned him his honour.

Karin Maruyama was a Japanese singer and tarento. She was born in Kōriyama, Fukushima Prefecture. She graduated from Shōshi Kōtō High School. She was nicknamed Rin-chan (りんちゃん). She was represented with Happy Strike. She had seven cases of malignant brain tumor removal surgeries. After she died, she was buried in Nichirinji Temple, Motomiya. Her sister is Miss iD 2016 finalist and Go Yoshida Award winner Yuka Maruyama.

Junaid Hussain was a British Pakistani black hat hacker and propagandist under the nom de guerre of Abu Hussain al-Britani who supported the Islamic State of Iraq and the Levant (ISIL). Hussain, who was raised in Birmingham in a family originally from Pakistan, was jailed in 2012 for hacking Tony Blair's accounts and posting his personal information online. Hussain left the UK around 2013 for Syria.

Willy Braciano Ta Bi was an Ivorian professional footballer who played as a defensive midfielder.

Mónica Janette Santa María Smith was a Peruvian model and TV hostess. She was born in Lima, Peru. From 1990 to early 1994, she co-hosted the Peruvian children's TV show Nubeluz.

Kamal Bamadhaj was a political science student and human rights activist, who was killed in the Dili Massacre in East Timor on November 12, 1991.

Kazushiza Horiguchi is a Japanese professional shogi player ranked 7-dan.