S omsri Lamsam is a member of the powerful and influential Lamsam family, one of Thailand's oldest and most prominent business dynasties. The family's vast fortune is centered on their controlling stake in Kasikornbank (formerly known as Thai Farmers Bank), which is one of the largest and most important commercial banks in Thailand. The bank was founded by her husband's family, and has been a pillar of the Thai financial industry for generations.

Somsri Lamsam is the widow of the late Banyong Lamsam, who served as the bank's long-time chairman and was a key figure in its modernization and growth. Upon his death, his stake in the family's holding company, which controls the bank, passed to his wife and children. Somsri is not involved in the day-to-day management of the bank, but her inherited shareholding makes her a billionaire and the matriarch of a key branch of this powerful banking family.