Nirmal Kumar (; born 14 December 1928, in Kolkata, India) is an Indian actor who is known for his work in Bengali cinema, radio and theatre. Often regarded as one of the greatest voice-over artists during 1960s and 1970s, Kumar lent his voice to numerous Bengali radio dramas. Winner of a BFJA Award, he made his big screen debut as Amit Roy in Madhu Bose's Bengali drama film Shesher Kabita (1953) based on Rabindranath Tagore's novel of the same name. He is also known for his roles in Bengali films such as Drishti (1955), Godhuli (1955), Kalindi (1955), Paresh (1955), Louhakapat (1958), Janmantar (1959), Kshaniker Atithi (1959), Kono Ekdin (1960) and Kamallata (1969).
Nirmal Kumar collaborated with Ajoy Kar in Paresh (1955). His collaboration with Tapan Sinha includes Upahar (1955), Louhakapat (1958), Kshaniker Atithi (1959), Apanjan (1968), Ekhoni (1971), Aandhar Periye (1973), Raja (1975), Sabuj Dwiper Raja (1979), Banchharamer Bagan (1980), Adalat o Ekti Meye (1982), Baidurya Rahasya (1985), Atanka (1986), Antardhan (1992) and Ajab Gayer Ajab Katha (1998). His collaboration with Partha Pratim Chowdhury includes Chayasurya (1963) and Dolna (1965). He collaborated with Rituparno Ghosh in Dahan (1998). He featured opposite Sumitra Devi in Gobinda Ray's Thakur Haridas (1959) and Suchitra Sen in Harisadhan Dasgupta's Kamallata (1969).
In 1949, Nirmal Kumar was an LDC at Calcutta High Court when he joined Gananatya on Sabitabrata Dutta's insistence. Several days later, he became a part of Bohurupee, which offered him the golden opportunity to observe Sombhu Mitra's acting style and voice modulation. Rabi Basu in his Satrang stated that Kumar excelled in all his radio dramas as he learned a substantial part of voice modulation from Mitra. The plays Kumar collaborated with Bohurupee were Pathik and Chera Tar, both penned by Tulsi Lahiri. Pathik was based on Rober Emmet Sherwood's The Petrified Forest. He, alongside Sabitabrata Dutta and Santosh Dutta formed a theatre group named Anandam.
In 1952, Sabitabrata Dutta advised Kumar to audition for Amit Ray in Madhu Bose's directorial venture Shesher Kabita (1953), based on Tagore's Shesher Kabita (1929). Kumar successfully auditioned for this role in Calcutta Movietone Studio. He was cast alongside Dipti Roy portraying the role of Labanya. The screenplay of the film was written by Nripendra Krishna Chatteejee. Though the film was a moderate success at the box office, it catapulted Kumar to stardom.
Following the success of Shesher Kabita, Kumar appeared in a string of Bengali films including Sushil Majumdar's Bhangagara (1954), Bikash Roy's Ardhangini (1955), Chitta Basu's Drishti (1955), Kartik Chattopadhyaay's Godhuli (1955), Naresh Mitra's Kalindi (1955), Ajoy Kar's Paresh (1955) and Tapan Sinha's Upahar (1955). He would continue to collaborate with Tapan Sinha in thirteen more films including Louhakapat (1958), Kshaniker Atithi (1959), Apanjan (1968), Ekhoni (1971), Aandhar Periye (1973), Raja (1975), Sabuj Dwiper Raja (1979), Banchharamer Bagan (1980), Adalat o Ekti Meye (1982), Baidurya Rahasya (1985), Atanka (1986), Antardhan (1992) and Ajab Gayer Ajab Katha (1998). He collaborated with Rituparno Ghosh in Dahan (1998).
Kumar collaborated with most of the iconic actresses of his time. He collaborated with Kaberi Bose in Chitta Basu's Drishti (1955). In Gobinda Ray's biographical drama Thakur Haridas (1959), he played Haridas Thakur alongside Sumitra Devi portraying the role of Lakshaheera. He starred as Gahar Gosai opposite Suchitra Sen playing the titular role in Harisadhan Dasgupta's Kamallata (1969).
He also featured opposite Arundhati Devi in Godhuli (1955), Chalachal (1956) and Janmantar (1959), Sabitri Chatterjee in Paresh (1955) and Upahar (1955), Supriya Devi in Kono Ekdin (1960), Bishkanya (1961), Abhisarika (1962), Dui Nari (1963) and Harano Prem (1966), Tanuja in Dolna (1965), Sumita Sanyal in Apanjan (1968) and Madhabi Mukherjee in Bindur Chhele (1973), Bon Palashir Padabali (1973) and Subarnalata (1981).