Last name SINGH: origin and meaning

Singh : Indian (northern states): originally a Kshatriya name but now widely adopted by Sikhs and other communities from Sanskrit siṃha ‘lion’ hence ‘hero’ or ‘eminent person’. It is freely added to Rajput and Sikh male personal names. In the US and elsewhere in immigrant communities it often functions as a Sikh surname.

Source : DAFN2 : Dictionary of American Family Names 2nd edition, ©2022 by Patrick Hanks and Oxford University Press