Update 10.45pm: The party of ousted Catalan leader Carles Puigdemont has claimed victory for the separatist bloc in the regional election.
Agusti Alcoberro, vice president of Catalan National Assembly, said: "We can say that pro-independence forces have won the elections."
He told a crowd gathered in Barcelona's Maritime Museum that "we demand the restitution of the (Catalan) government and the release of the political prisoners".
Spain's government deposed Catalonia's regional government after the Catalan parliament made an illegal declaration of independence on October 27.
A judge also imprisoned the then president of the Catalan National Assembly, Jordi Sanchez.
He resigned his post to run in the election.
Update 10pm: Pro-independence parties looked set to regain their majority in Catalonia's parliament after 50% of the votes had been counted.
The regional electoral board said the anti-independence Ciutadans (Citizens) party, led by 36-year-old lawyer Ines Arrimadas, is likely to win the highest number of votes for a single party, and 35 seats in the 135-member chamber.
But it said the pro-independence ticket led by fugitive former Catalan president Carles Puigdemont would garner 34 seats for the Together for Catalonia group. In third place would be the pro-secession leftist republican ERC party with 32 seats.
With the help of the radical pro-independence radical CUP party, which could get four seats, the pro-secession bloc is set to regain a majority in parliament.
The regional election is being closely watched in and outside Catalonia as a crucial test of strength for the region's powerful secession movement.
Earlier: Voting has finished in a crucial election in Spain's Catalonia region, as polling stations closed at 7pm.
The regional election is being closely watched in and outside Catalonia to see if support for a separatist push will grow, fuelling much political tension with Spain.
Catalan authorities said voting turnout was up by more than five percentage points at 6pm, with 68.3% of Catalan voters having cast ballots, compared to 63.12% in the last election in 2015.
Surveys in recent weeks had predicted record turnout numbers.
The day passed off without any major incident beyond lengthy queues at polling stations at peak times of the day.