A. P. Venkateswaran comes from a Tamil Brahmin family with roots in a small Palakkadu hamlet of Ayilam, in the south Indian state of Kerala. His father, A. S. Panchapakesa Ayyar was a former Madras High Court judge turned civil servant and Venkateswaran was born at Brahmapur, while his father was staying in Odisha with his mother, Vedanayaki Ammal. Venkateswaran was good at studies and he secured three post graduate degrees in Science, Economics, and Political Science from the Madras Christian College before joining Indian Foreign Service on 2 April 1952, at the age of 22. After joining the service, Venkateswaran continued his studies at Oxford on International Law (1952–53) and at the UCL School of Slavonic and East European Studies, London (1953–54).
Venkateswaran was married to Usha and the couple had a daughter, Kalpana, who is settled in the US. He died on 3 September 2014, at Bangalore, succumbing to a cardiac arrest. His mortal remains were cremated at Wilson Garden Crematorium in the city.
Venkateswaran was a Fellow of the Center for Industrial Affairs at Harvard University from 1974 to 1975. He has also written several articles on international politics in journals and magazines.
One year after he assumed office as the Foreign Secretary of India, Venkateswaran made a public statement that the Indian Peace Keeping Force operations in Sri Lanka was a mistake, a statement which appeared to have irked Rajiv Gandhi, then Prime Minister of India. Weeks later, when asked by a Pakistani journalist about the impending Pakistan visit for the SAARC summit, announced earlier by Venkateswaran, Rajiv Gandhi replied with the now famous words,
Soon, you will be talking to a new foreign secretary
The declaration generated much publicity and had no precedence where the termination of service of a Class I civil services officer being announced at a press conference. Venkateswaran, present at the press conference, sent the letter of his resignation to the Prime Minister's office immediately. The incident attracted worldwide media interest. Years later, Venkateswaran commented that the decision to send IPKF to Sri Lanka was a mistake which finally led to the assassination of Rajiv Gandhi.
Venkateswaran has served in the Indian foreign offices across the globe, except in South American continent, and was the Indian Ambassador in the US, China and Syria. After his Embassy stints, he served as the Indian representative in the United Nations before returning to India, in 1986, when he was made the Foreign Secretary of India, the highest job in the Indian Foreign Service, during Rajiv Gandhi's term as the Prime Minister of India.
Venkateswaran resigned from Indian Government service in 1987 after which he founded Asia Centre, a think tank of diplomats and intellectuals, based in Bangalore.