Rolandas Paksas ([rɔˈɫɐ̂ˑndɐs ˈpaːksɐs] (listen); born 10 June 1956) is a Lithuanian politician who was President of Lithuania from 2003 to 2004. He was previously Prime Minister of Lithuania in 1999 and again from 2000 to 2001, and he also served as Mayor of Vilnius from 1997 to 1999 and again from 2000 to 2001. He led Order and Justice from 2004 to 2016 and was a Member of the European Parliament from 2009 to 2019.

A national aerobatics champion in the 1980s, after the collapse of the Soviet Union, Paksas founded a construction company, Restako. In 1997, he was elected to Vilnius City Council for the centre-right Homeland Union and became mayor. In May 1999, Paksas was appointed Prime Minister, but resigned five months later after a disagreement over privatisation. Paksas joined the Liberal Union of Lithuania (LLS) in 2000. The LLS won the 2000 election, and Paksas became PM again, but he left within seven months after another dispute over economic reforms.

In 2002, Paksas founded the Liberal Democratic Party, and ran for the presidency, winning the run-off against incumbent Valdas Adamkus in January 2003. It emerged that he had granted citizenship to a major campaign donor, leading to his impeachment and removal from office in April 2004. He was the first European head of state to have been impeached. Barred from the Seimas, Paksas was elected to the European Parliament in 2009, while leading his party, now called Order and Justice (TT). His lifetime ban from the parliament was ruled to be disproportionate measure by the European Court of Human Rights in 2011. In 2018 the amendment which would allow for Paksas to run for parliamentary seat is to be submitted. But he will not be allowed to run for president or become the speaker of the Parliament. He is considered to be the worst President of Lithuania in modern history.