Uttam Kumar married Gauri Chatterjee in 1941. Later, he lived with actress Supriya Devi when he left his home at Girish Mukherjee road in 1963 till his death.

He came out with an authorised biography Aamar Ami in 1979–80. He had a phenomenal fan base which continues even to this day. In 1960, he started writing an autobiography named Harano Dinguli Mor (My Bygone Days), but could not complete it. Parts of that book were published by the magazine Nabokallol. On the day Uttam died, the original manuscript was stolen. Later, a member from Times of India had found the manuscript and the national library helped to find old editions of Nabakallol and then the incomplete book was finally published in the 37th Calcutta Book Fair. As a singer, he recorded songs for the AIR – All India Radio – and very recently, an album of Tagore songs (Rabindrasangeet) sung by him, has been brought out.

Shonar Harin (1959) saw Supriya Devi (who would win great accolades for her performance in Ritwik Ghatak’s Meghe Dhaka Tara the following year) play the lead opposite Uttam Kumar. As they began to act in more films together, the two got involved off-screen as well. In 1963, Uttam left his family home at Girish Mukherjee Road, Bhowanipur and stayed with Supriya for the next 17 years till his death. They starred together in several other films like Uttarayan, Chiradiner, Agni Sanskar, Suno Baranari, Kal Tumi Aleya, Lal Pathor, Andha Atit, Sudhu Ekti Bochhor, Mon Niye, Bilambita Loy, Bhola Maira, Sanyasi Raja, Bon Palashir Padabali, Sister, Jibon Mrityue, Bagh Bandir Khela.

He explored new avenues of film-making by trying his hand at production, singing, composing music, screenplay writing and directing. The success of his Indian films as producer — Harano Sur, Saptapadi, Bhrantibilash, Jotugriha (1964), Grihadah — won greatest acclaim. On producing Chhoti Si Mulaqat in 1967, which was a Hindi film starring Uttam and Vyjayanthimala, Uttam almost used up all his savings, since the film had to be shot in colour and was shot in extravagant locations. Both Uttam and Vyjayanthimala had huge hopes associated with the film, but the film was a flop leading to great disappointment for Uttam Kumar. It was later said that this flop was one of the main reasons for triggering the heart attack, which ultimately led to his death. Later, Uttam directed much-lauded films such as Sudhu Ekti Bochhor and Bon Palashir Padaboli. He composed music for the film Kaal Tumi Aleya in which Hemanta Mukherjee and Asha Bhosle sang to his tune.

A workaholic, he was rumoured to have said that his preferred demise would be on the floor of a studio, doing what he loved best: acting. While filming Ogo Bodhu Shundori in 1980 Uttam Kumar suffered a stroke and was admitted to the Belle vue Clinic. The doctors did their best for 16 hours but he died that night on 24 July 1980 at the age of 53. As his dead body found its way across Bhowanipur and finally to the Keoratala Burning Ghat, traffic in Kolkata came to a halt as thousands flocked the streets to pay their respects and have a last glimpse of the legend.

Tollygunge Metro station in Kolkata was renamed as Mahanayak Uttam Kumar Metro Station in his honour. There is a theatre (Uttam Mancha) named after him in Kolkata. A life-size statue has been erected near Tollygunj metro station which has recently been renamed after the iconic actor by the Central Railway Ministry. Besides, Shilpi Sansad, the actor’s pet project of safegurading the artistes especially the poor and the old, is active still. Celebrating the 89th birth anniversary of Uttam Kumar, the Department of Posts in 2009, released a series of new postal stamps featuring the actor on them.The Department of Posts also released a brochure on the Uttam Kumar Stamp release with a note that says “Uttam Kumar – The Legend of Indian Cinema”. “The government of India” release 19 June 2015 “UTTAM” AWARD for Best acting. In the year of 2016, a television series called ‘Mahanayak’ was telecast. It was based on his life.