Srirasmi Suwadee was born in Samut Songkhram Province to a family of modest means. She was the third of four children born to Apiruj and Wanthanee Suwadee, and has Mon descent from her mother's side.
She attended Bangkok Business College and in 1993, at age 22, entered the service of Vajiralongkorn as a "lady-in-waiting." Srirasmi enrolled in Sukhothai Thammathirat Open University in 1997 and graduated in 2002 with a bachelor’s degree in management science. Vajiralongkorn personally bestowed her with her diploma. In 2007, she received a Master of Science degree in Family and Child Development from Kasetsart University.