The 21st National Film Awards, presented by Directorate of Film Festivals, the organisation set up by Ministry of Information and Broadcasting, India to felicitate the best of Indian Cinema released in the year 1973.^[1] Ceremony took place in October 1974 and awards were given by Prime Minister Indira Gandhi.

Prior to 21st National Film Awards, there used to be regional committees at Bombay (Mumbai), Calcutta (Kolkata) and Madras (Chennai), the recommendations of which were then considered by central committee. To avoid this long-winded process, regional committees were discarded.

Two different committees were formed for feature films and short films, headed by Romesh Thapar and S. K. Kooka respectively.^[1]

• Jury Members: Feature Films
  • Romesh Thapar (Chairperson) • Usha Bhagat • Teji Bachchan • Ismat Chughtai • M. Yunus Dehlvi • Ashis Burman
  • Firoze Rangoonwalla • Dina Pathak • B. V. Karanth • T. S. Pillai • T. K. Mahadevan • J. Swaminathan
  • Dileep Padgaonkar • Subodh Mukherjee • U. Visweswar Raw • Asim Paul • Tarun Majumdar • Ananta Patnaik
  • Illindula Saraswathi Devi • M. Bhaktavatsala • Sai Paranjpye • K. R. K. Menon • O. V. Vijayan
• Jury Members: Short Films
  • S. K. Kooka (Chairperson) • Balwant Gargi • Nalni Soni • Komal Kothari

Awards were divided into feature films and non-feature films.

President's gold medal for the All India Best Feature Film is now better known as National Film Award for Best Feature Film, whereas President's gold medal for the Best Documentary Film is analogous to today's National Film Award for Best Non-Feature Film. For children's films, Prime Minister's gold medal is now given as National Film Award for Best Children's Film. At the regional level, President's silver medal for Best Feature Film is now given as National Film Award for Best Feature Film in a particular language. Certificate of Merit in all the categories is discontinued over the years.