Sein Lwin was born on 27 January 1924 in Kawkayin village, Paung, Mon State then under the British Raj to parent Shwe Yin and his wife Ma Ma Gyi.
Sein Lwin was born on 27 January 1924 in Kawkayin village, Paung, Mon State under British rule to parents Shwe Yin and Ma Ma Gyi.