Subbaraju was born in Bhimavaram, to Penmatsa Ramakrishnam Raju and Vijayalakshmi. He has one elder brother, Pullam Raju, who is a Sanskrit teacher. Subbaraju did his education in D. N. R. College, Bhimavaram. He did his Bachelor's degree in Mathematics before doing a computer course and joining Dell Computers, Hyderabad.
Subbaraju's introduction to the cinema world was an accident. Tollywood director Krishna Vamsi's personal assistant asked him to fix a computer issue for Krishna Vamsi's personal computer. After going to Krishna Vamsi's house, Subbaraju was offered a small role in Krishna Vamsi's Khadgam.