Born to a wealthy landholding and mining family, Kotelawala had a difficult childhood with the suicide of his father and the financial difficulties that followed.

A year later he succeeded his cousin, Dudley Senanayake, as the third Prime Minister of Ceylon, serving until his party lost the general election in 1956.

Having donated his home, Kandawala, to the state to form a defense university, he was granted the rank of general on his deathbed.

After he was forced out of the management of the Attygalle estates by the family, Kotelawala Snr started his own business ventures including the Ceylon-Japan Trading Company.

Alice Kotelawala who had converted to Christianity slowly built up the family wealth through careful management of their remaining land holdings and the share of the Kahatagaha graphite mine, which she received from her younger sister Ellen and brother-in-law, Fredrick Richard Senanayake.

[2][4] Young Kotelawala attended Royal College, Colombo, representing the school in cricket, tennis, boxing and football.

He remained in Europe for five years, spending most of that time in England and France, and attended Christ's College, Cambridge to study agriculture.

[5][6] In a time when serving in the volunteer forces was prestigious and a gentlemanly pursuit, Kotelawala gained a commission as a second lieutenant in the Ceylon Light Infantry on 15 September 1922.

Kotelawala as the Minister of Communications and Works, became a member of the Ceylon's War Council and served as the Commander-in-Chief of the Essential Services Labor Corp.[9] He provided his home, Kandawala to function as the officers mess for the wartime RAF station at Rathmalana.

[10][11] When Senanayake suddenly died on 22 March 1952, Kotelawala expected to succeed him as prime minister, given he was the leader of the house and the most senior member of the UNP.

[10] The following year, the Senanayake government faced major civil unrest with left-wing parties launching the 1953 Hartal in August.

On 12 August 1953 civil disobedience, strikes and demonstrations started throughout the island by trade unions against the proposed elimination of the subsidy on rice by the government.

He formed the Ceylon Railway Engineer Corps and Post and Telegraph Signals to minimise the effects on transport and communication in the event of trade union action.

He hosted Queen Elizabeth II and the Duke of Edinburgh in Ceylon during their Royal Commonwealth Tour in April 1954, using the occasion to request the appointment of a Ceylonese Governor-General when Lord Soulbury's tenure ended.

His uncontroversial first speech at the conference was written by journalists at the Lake House group, However, he had been influenced by the British Government, as well as by his US-aligned permanent secretary Gunasena de Soyza to make anti-Communist remarks.

In a private conversation with the prime ministers of Pakistan, India, Burma, and China, he asked the Chinese premier Zhou Enlai if he wanted to bring Communism to Tibet.

Zhou replied that it was impractical and undesirable and that the PRC had gone to Tibet because it was "an integral part of the Chinese state" and because it had historically been threatened by "imperialist intrigues" from the British Empire and Imperial Russia.

Kotelawala retained his parliamentary seat having been reelected from the Dodangaslanda electorate, however, he did not attend parliament often since Dr N. M. Perera had become the Leader of the Opposition.

In 1979, Lieutenant General Denis Perera, Commander of the Sri Lankan Army approached Kotelawala with the proposal of donating his home Kandawala and its 50 acres estate to the state to establish a Defence university.

On 5 October, Kotelawala's coffin which was kept at Kandawala was moved to Parliament House to lay in state, before final rites at Independence Square with full military honours.

Although the marriage was not successful, ending in divorce, it produced a daughter, Lakshmi Kotelawala, who married Henry Gerald Kotalawala.

His Orders, Decorations, Medals and other memorabilia are on display at the General Sir John Kotelawala Defence University.