The non-binding vote went ahead after Spain's constitutional court ruled out holding a formal referendum in the autonomous north-eastern region.
More than two million people out of an estimated 5.4 million eligible voters took part in the ballot.
Catalan leader Artur Mas hailed the poll "a great success" that should pave the way for a formal referendum.
"We have earned the right to a referendum," he told cheering supporters.
"Once again Catalonia has shown that it wants to rule itself."
The BBC's Patrick Jackson reports from a polling station in Catalonia
He added: "I ask the people in the world, I ask the media and I also ask the democratic governments in the world to help the Catalan people decide its political future."