Dinesh Chandra Rupasinghe Gunawardena (Sinhala: දිනේෂ් චන්ද්‍ර රූපසිංහ ගුණවර්ධන, Tamil: தினேஷ் சந்திர ரூபசிங்க குணவர்தன; born 2 March 1949) is a Sri Lankan politician who served as Prime Minister of Sri Lanka from 2022 to 2024. He also held the positions of Minister of Public Administration, Home Affairs, Provincial Councils and Local Government. Gunawardena has been leader of the left-wing Mahajana Eksath Peramuna (MEP) party since 1983, was briefly the de facto leader of the Sri Lanka Podujana Peramuna from 2022 to 2023, and has taken cabinet positions under several previous governments, including Leader of the House from 2020 until 2022.

Born in a political family, the son of Philip Gunawardena and Kusumasiri Gunawardena, and nephew of Vivienne Goonewardene, he was educated at Royal College, Colombo and later at the University of Oregon, where he advocated pacifism in the Vietnam War. Entering politics in 1983 as a Member of Parliament from Maharagama and later Colombo, his first role in government was as Minister of Transport under Ratnasiri Wickremanayake.

In 2022, Gunawardena was appointed the Prime Minister after former President Gotabaya Rajapaksa resigned amidst the ongoing economic crisis and Ranil Wickremesinghe was elected as his successor. In September 2024, Gunawardena resigned.

Gunawardena was born into the political Gunawardena family on 2 March 1949. His father, Philip Gunawardena, was known as "the Father of Sri Lankan socialism" and a key independence figure, and his mother, Kusumasiri Gunawardena, was a member of parliament. His aunt, Vivienne Goonewardene, was often considered the "foremost female figure in the Sri Lankan left".

Educated at Royal Primary School, Colombo and Royal College, Colombo, he went on to study at the Netherlands School of Business. He also graduated with a B.B.A. from the University of Oregon, and whilst in the United States, became involved in student activism, taking part in anti-Vietnam War protests.

Gunawardena later married Ramani Wathsala Kotelawela from the Kotelawela/Jayawardena family; who is the niece of General Sir John Kotelawela, the third Prime Minister of Sri Lanka. They had one son, Yadamini, and one daughter, Sankapali. Ramani died of undiagnosed hepatitis in the mid-1980s.

After graduation from the University of Oregon, Gunawardena worked in New York City, but returned to Sri Lanka in 1972 after his father's death. He was appointed to the Mahajana Eksath Peramuna's (MEP) central committee in August 1973, and became general-secretary of the MEP in 1974.

Gunawardena was the MEP's candidate in Avissawella at the 1977 parliamentary election, but failed to get elected until he ran as the MEP's candidate in the Maharagama Electoral District at the 1983 by-election, winning and entering Parliament. During the 1989 parliamentary election, Gunawardena successfully ran as one of the MEP's candidates in the multi-member Colombo Electoral District. He was again one of the MEP's candidates in Colombo District at the 1994 parliamentary election, but the MEP failed to win any seats in Parliament.