Yoweri Museveni has been in office for more than a quarter of a century, having seized power at the head of a rebel army.
He won a fresh term in office in presidential elections in February 2011, having amended the constitution before the 2006 election to remove the previous limit on the number of terms a president could serve.
In 2011 he took 68% of the vote. Challenger Kizza Besigye - who won 26% - rejected the result, alleging election fraud. EU observers said there had been improvements in the conduct of the electoral process since 2006, but still noted some shortcomings.
Mr Museveni has been credited with restoring relative stability and economic growth to Uganda following years of civil war and repression under Milton Obote and Idi Amin before him.
Mr Museveni co-founded one of the rebel groups which, with the help of Tanzanian troops, ousted Idi Amin in 1979. He then formed a new rebel army which eventually seized power in 1986.
His National Resistance Movement ran Uganda as a one-party state until a referendum brought back multi-party politics in 2005. He won presidential elections in 1996, and again in 2001, 2006 and 2011.
He has faced UN criticism his role in the conflict in DR Congo between 1998 and 2003. More recently Uganda has been accused of aiding rebels there.
The government has also faced growing criticism for failing to take action against senior officials implicated in corruption scandals.
There is speculation that Mr Museveni is grooming his son Muhoozi Kainerugaba to succeed him.
Born in western Uganda in 1944, Yoweri Museveni studied political science in Tanzania and fought with the Front for the Liberation of Mozambique (Frelimo), where he picked up the techniques of guerrilla warfare.