He was born at Musapur village in Sandwip Island in Chittagong District of Bengal Province in British India (in the present day Bangladesh). His father's name was Mansur Ali and Mother's name was Chuna Bibi. He was schooled at Noakhali Zilla School. In 1918, he was appointed joint secretary of "Bangio musalman sahitya Samiti". In 1920, along with Kazi Nazrul Islam he started a new magazine, Navayug. Later, when another magazine, Dhumketu was launched by Nazrul in 1922, he contributed to it using the pseudonym "Dvaipayana".
Ahmad was one of the founders of the Communist Party of India. In 1922, the Bharat Samyatantra Samiti was formed in Calcutta with Kakababu as its secretary. In 1924, he was sentenced to four years in prison because of his role in the Kanpur Bolshevik Conspiracy Case along with S.A. Dange, Nalini Gupta and Shaukat Usmani. He was released due to illness in 1925. In November, 1925 he, along with Qazi Nazrul Islam, Hemanta Kumar Sarkar, and others, organized the Labour Swaraj Party in Bengal.
On 20 March 1929, the British colonial government arrested 31 labour activists and sent them to Meerut for trial. Kakababu was the chief accused, along with S.A. Dange, Shaukat Usmani, P.C. Joshi and others, was convicted in this so-called Meerut Conspiracy Case. He was released in 1936. He had served the longest term in jail as the Chief Accused in the Meerut Trial.
He was still Muslim during the time of the partition of India in 1947. He moved to Calcutta (now Kolkata) rather than staying in East Pakistan (now Bangladesh). On 25 March 1948, the Communist Party of India was banned by the Government of India and Kakababu was imprisoned. He was released from prison in 1951. He was again arrested and imprisoned for two years in 1962, and another time for two years in 1965. He was imprisoned several times in post-Independence India by the Congress government.
He died in Calcutta in 1973, aged 84.