In power since 2010, Artur Mas was re-elected as regional head in December 2012 after his centre-right Convergence and Union (CiU) alliance agreed an unlikely pact with the centre-left Republic Left (ERC) party.
Despite their traditional ideological differences, both pro-independence parties pledged to work towards holding a referendum on secession from Spain, in the face of fierce opposition from the Spanish government.
In order to pave the way for the referendum, the regional parliament in 2013 passed a declaration stating that the people of Catalonia have a democratic right to decide on their sovereignty.
After the Spanish constitutional court ruled that the planned referendum would be unconstitutional, Mr Mas said the vote - held in November 2014 - would have non-binding nature.
The exercise resulted in a 80% "yes" vote in favour of independence.
Artur Mas hailed the result as a "great success". Spanish Justice Minister Rafael Catala dismissed it as a "useless sham".
New regional elections were called for September 2015, to win support for a possible unilateral declaration of independence.
Mr Mas has headed Catalonia's regional executive since December 2010, when his centre-right Convergence and Union alliance defeated the Socialist Party of his predecessor, Jose Montilla, in legislative elections.
For much of his career Mr Mas did not favour full independence, but has changed his view in recent years. Since 2007, Mr Mas has spearheaded a push to revitalise Catalan nationalism.
Born in Barcelona in 1956, Mr Mas has an economics degree. He has a long career in municipal and then regional-level politics.
An alliance of moderately nationalist parties, his Convergence and Union governed Catalonia continuously from the re-establishment of regional autonomy in 1980 until 2003, when it lost power to the Socialists.
Catalonia's autonomy statute gives the regional authority - the Generalitat - broad powers of self-government within Spain, especially on matters such as culture, education, health, transport, public safety and commerce. It is the only Spanish region to have its own police force, the Mossos d'Esquadra.
President of regional government: Artur Mas i Gavarro