Rajendra Nath Malhotra was a comedian actor in Indian Hindi and Punjabi films. His family was from Peshawar but settled in Jabalpur in Madhya Pradesh. His studied in college at Darbar College, Rewa where Arjun Singh (a Congress politician) and R.P. Agarwal were his class mates.
Rajendra Nath's older brother Prem Nath went to Mumbai and became an actor, so Rajendra Nath joined him, they were good friends of Raj Kapoor, Shashi Kapoor and Shammi Kapoor. Rajendera Nath and Prem Nath's sister Krishna married actor-director, Raj Kapoor. He had also another brother 'Narendranath' who also became actor usually played some villain's role in the movies.
Initially Rajendra Nath struggled to get roles till Sashadhar Mukherjee offered him a comedian's role in Dil Deke Dekho, a film directed by Nasir Hussain, starring Shammi Kapoor and Asha Parekh. In Nasir Hussain's Jab Pyar Kisi Se Hota Hai he along with Asha Parekh were a regular in many Nasir Hussain films, like Phir Wohi Dil Laya Hoon, Teesri Manzil, Baharon Ke Sapne, Pyar Ka Mausam. He once played a buffoon called Popatlal in Jab Pyar Kisi Se Hota Hai and the name grew so synonymous with Rajendra Nath that he used this name in TV series Hum Paanch.
He then did a large number of films, mostly comic roles, such as in An Evening in Paris and Phir Wohi Dil Laya Hoon. One of his most applauded performances was in Manoj Kumar's Purab Aur Paschim though may not be in a full fledged comedy role.
He starred in a number of Punjabi films such as Jatt Punjabi. He also acted in the very famous TV serial Hum Paanch as Mr. Popat Lal.
He died on 13 February 2008 from a cardiac arrest.