Singh is an Indian Foreign Service officer of the 1976 batch. She is a German speaker and served in various positions at the Indian embassies at Bonn, Accra, Paris, and Bangkok. She was India's Consul general at Milan during 2000–04. She has also served as India's High Commissioner to Australia. In Delhi she has served on the Ministry's Economic Co-ordination Unit and dealt with Nepal, West Europe and the EU as director, undersecretary and joint secretary. Her tenure as High Commissioner to Australia was marked by turbulence in Indo-Australian ties following racial attacks on Indian students and later by the Australian Labour Party's decision to make an exception for India regarding the sale of uranium. She has a reputation for toughness, volunteering as a liaison officer on a rain-hit Kailash Manasarovar Yatra in 1983, taking a tough stance with the Australian authorities on dealing with the racial attacks against Indians there, and, as joint secretary handling Western Europe, she advocated India's stance of not accepting prescriptive aid from small European Union nations.
Foreign Secretary
In 2013 Sujatha Singh succeeded Ranjan Mathai as Foreign Secretary of India. She was appointed over S. Jaishankar, and assumed office on 1 August 2013. The fact that she had never served as ambassador to any of India's neighbouring nations was seen as a challenge, and it was said that she had been favored for the post for being a woman, and the Congress government under Sonia Gandhi was absolutely diligent in promoting women wherever remotely possible. Singh was the third female officer to head the Indian diplomatic corps after Chokila Iyer and Nirupama Rao. In the normal course, she should have retired from the Indian Foreign Service in July 2014 upon her 60th birthday, but appointments to the position of foreign secretary are usually made for a tenure of two years, and such was the case with her. She thus received an extension in service of thirteen months, and her two-year term as Foreign Secretary should have ended in August 2015. However, a government order on 28 Jan 2015, issued by the newly elected government of Narendra Modi, terminated her extended service and appointed another person to the post of Foreign Secretary. This was S. Jaishankar, who as Indian Ambassador to United States had played a key role during Indian Prime MinisterModi's visit to the US, and in US President Obama's visit to India.