He was born in 1905 in Sylhet (formerly India, now Bangladesh) and was the son of Muhammad Cassie Ali and Babe Ali. Youssif Ali worked as a sailor, or ‘lascar’, on board merchant ships. During the 1920s, he moved to England and married Ethel Emma Wallace.

Once settled in London, Ali moved between three different careers. 

From a court interpreter to a doorman at the Veeraswamy, an exclusive and political central London restaurant, to a Royal Air Force Leading soldier, he demonstrated bravery and honour during World War II. Ali's story is like that of hundreds and thousands of Muslim Sylhet merchant sailors who experienced a similar life in London, with a vast majority losing their lives whilst serving in World War II for Britain.

Ali suffered a coronary thrombosis and was admitted to the British Military Hospital in Paris. Transferred to British Military Hospital Calais for evacuation to the UK; he was then admitted to Barningham Military Hospital and then to RAF Hospital Halton, where he died (via Jon Heyworth). He was the last soldier buried at the Muslim Burial Ground (Brookwood Cemetery) on 12 May 1947.