Belousov (or Beloussov), feminine: Belousova is a Russian-Polish patronymic surname formed from the nickname Belous (which also became a surname) derived from Belye Usy (Russian: Белые Усы), (Polish: Białe wąsy) "White Moustache".
Notable people with this surname include:
- Alexandr Belousov (born 1998), Moldovan footballer
- Andrey Belousov (born 1959), Russian politician and economist
- Anna Belousova (born 1996), female Russian swimmer
- Boris Belousov (born 1934, Soviet politician
- Boris Belousov (cosmonaut) (1930–1998), Soviet cosmonaut
- Boris Pavlovich Belousov (1893–1970), Soviet chemist
- Denys Byelousov (born 1996), Ukrainian footballer
- Dmitri Belousov (born 1980), Russian footballer
- Georgi Belousov (born 1990), Russian ice hockey player
- Igor Belousov (1928–2005), Soviet politician
- Ilya Belousov (born 1978), Russian football midfielder
- Irina Belousova (born 1954), Ukrainian politician
- Ludmila Belousova (1935–2017), Russian figure skater
- Mikhail Belousov (born 1953), Russian politician
- Piotr Belousov (1912–1989), Soviet, Russian painter, graphic artist, and art teacher
- Sergey Belousov (born 1990), Russian association footballer
- Sonya Belousova (born 1990), Russian-born composer, pianist and recording artist
- Vadim Belousov (born 1960), Russian politician
- Valentin Danilovich Belousov (1925–1988), Moldavian Soviet mathematician
- Valeriy Belousov (born 1970), decathlete from Russia
- Valery Belousov (1948–2015), Russian professional ice hockey coach and player
- Vladimir Belousov (1907–1990), Soviet geologist
- Vladimir Belousov (ski jumper) (born 1946), Soviet ski jumper
- Yaroslav Belousov (born 1991), Russian political prisoner
- Yevgeny Vladimirovich Belousov (born 1962), Soviet luger
- Yuri Leonidovich Belousov (1945–2000), Soviet and Russian researcher and engineer
- Zhenya Belousov (1964–1997), Soviet and Russian pop singer