Somnath Chatterjee was educated at Mitra Institution School (Calcutta), Presidency College and then the University of Calcutta in Calcutta. He also attended Cambridge University and has been awarded an honorary fellowship of Jesus College. He was called to the bar in England and was a litigating barrister at the Calcutta High Court before joining active politics.
His father Nirmal Chandra Chatterjee was the president of the Akhil Bharatiya Hindu Mahasabha, an organisation that championed Hindu causes and is a forerunner of today's BJP. Later he left Hindu Mahasabha to join left politics and was elected to the Parliament with CPI(M) support.