Narayana Padaiyatchi Rathnam (c. 1897 – August 1950), popularly known as "Kali" N. Rathnam, was a Tamil stage and film artist known for his roles as a comedian in Tamil movies of the 1930s and 1940.
Rathnam was born at Malaiyappanallur near Kumbakonam in Tanjore District in the year 1897 to Narayana Padayatchi and Thangathammal. His parents were agriculturists and Rathanm was acquainted with rural songs and folk arts from a very early age. As a young boy, Rathnam learned to act from a stage actor named Parameswaran Iyer. Seeing Rathnam perform the role of Kali in a stage play, Iyer christened him "Kali" N. Rathnam.
Rathnam joined the Madurai Original Boys Company in 1923 and acted in Pathi Bhakthi (1936), the first movie produced by the Company. Rathnam's second movie was Mannarswami (1936). But Rathnam's first hit was Chandrakantha (1936). Following the success, Rathnam acted in hit movies such as Uthama Puthiran, Sathi Murali (1940), Sabapathy (1941), Manonmani (1943), Burma Rani and Sri Murugan.