Lie was born in Kristiania (now Oslo) on 16 July 1896. His father, carpenter Martin Lie, left the family to emigrate to the United States in 1902, and was never heard from again. Trygve grew up under poor conditions together with his mother Hulda and a sister who was six at the time. His mother ran a boarding house and café in Grorud in Oslo.

Lie joined the Labour Party in 1911 and was named as the party’s national secretary soon after receiving his law degree from the University of Oslo in 1919. Lie was editor-in-chief for Det 20de Aarhundre (‘The 20th Century’) from 1919 to 1921. From 1922 to 1935 he was a legal consultant for the Workers’ National Trade Union (named Norwegian Confederation of Trade Unions from 1957). He chaired the Norwegian Workers’ Confederation of Sports from 1931 to 1935.

Lie married Hjørdis Jørgensen (1898–1960) in 1921. The couple had three daughters; Sissel, Guri, and Mette.

In local politics he served as a member of the executive committee of Aker municipality council from 1922 to 1931. He was elected to the Norwegian Parliament from Akershus in 1937. He was appointed Minister of Justice when a Labour Party government was formed by Johan Nygaardsvold in 1935. Lie was later appointed Minister of Trade (July to October 1939) and Minister of Supplies (October 1939 to 1941).

When Nazi Germany invaded Norway in 1940, Lie ordered all Norwegian ships to sail to Allied ports. In 1941, Lie was named as Foreign Minister of the Norwegian government-in-exile, and he remained in this position until 1946.

Lie led the Norwegian delegation to the United Nations conference in San Francisco in 1945 and was a leader in drafting the provisions of the United Nations Security Council. He was the leader of the Norwegian delegation to the United Nations General Assembly in 1946. On 1 February 1946, he was elected as the first Secretary-General of the United Nations as a result of a compromise between the major powers, having missed being elected President of the first General Assembly by only a small margin.

As Secretary-General, Lie supported the foundations of Israel and Indonesia. His passionate support for Israel included passing secret military and diplomatic information to Israeli officials. He sent 50 members of the United Nations guard force from Lake Success to assist the Mediator in supervising the Truce in the former British Mandate of Palestine in 1948 and the “UNTSO”, the first peacekeeping operation was established by the United Nations. He worked for the withdrawal of Soviet forces in Iran and a ceasefire to fighting in Kashmir. He attracted the ire of the Soviet Union when he helped gather support for the defence of South Korea after it was invaded in 1950 and later worked to end the Soviet boycott of UN meetings, though his involvement had little to do with the eventual return of the Soviet Union to the UN. He was opposed to Spain’s entry into the United Nations because of his opposition to Francisco Franco’s government.

On 1 November 1950, over objections by the Soviet Union, the UN General Assembly voted by 46 votes to 5 (and 8 abstentions) to extend Lie’s term of office. The vote was a consequence of an impasse in the Security Council in which the Soviet Union refused to consider Lie due to his involvement in the Korean War, while the US refused to accept any candidate except Lie. The Soviet Union subsequently refused to acknowledge Lie as Secretary-General and, having been accused by Joseph McCarthy of hiring “disloyal” Americans – an allegation that he attributed to the pressing need for civil servants following the establishment of the UN – Lie resigned on 10 November 1952.

Abraham Feller, General Counsel and Principal Director, Legal Department, United Nations Secretariat, was “reportedly” a “close friend” of Alger Hiss. On 14 November 1952, just days after Lie’s resignation from the UN, Feller committed suicide by jumping out of the window of his apartment in New York City.

Lie died on 30 December 1968 of a heart attack in Geilo, Norway. He was 72 years old.

“Trygve Lie′s Square” is located in Furuset center in Oslo. In the square stands the bronze statue of Trygve Lie, which was created by the Norwegian artist Nicolaus Widerberg and erected in 1994. Trygve Lie Gallery and Trygve Lie Plaza are both located in New York City.