Turkish PM Recep Tayyip Erdogan has vowed to continue reforms and efforts to join the European Union, following his party's election victory.
Mr Erdogan said that "democracy has passed a very important test"
Mr Erdogan also said his Islamist-rooted AK Party would seek national unity and respect Turkey's secular constitution.
Unofficial results gave the AK Party about 47% of the vote, prompting wild street celebrations by supporters.
Opponents have warned that an AKP win could undermine Turkey's secularism.
The election was called after opposition parties in parliament blocked the AK Party's nominee for the post of president, causing political deadlock.
One of the new parliament's first tasks will be to decide what to do about the post of the presidency.
But despite his election win, Mr Erdogan will lack the two-thirds parliamentary majority to force through his presidential choice.
In the capital Ankara, Mr Erdogan told jubilant supporters that the AKP victory was a triumph for democracy.
He promised to "press ahead with reforms and the economic development that we have been following so far".
"We will continue to work with determination to achieve our European Union goal," he said.
The prime minister also vowed to continue the fight against Kurdish rebels in the east of Turkey.
Although the AKP has been returned to power with a larger share of the vote, the presence of a third political party in the parliament means it will have fewer seats, the BBC's Pam O'Toole says.
She adds that the presence of Kurdish deputies and the Nationalist Action Party could be a potentially explosive mix in parliament.
The AKP's 47% means it would get up to 341 seats in the 550-member parliament.
Two opposition parties won the 10% share needed to guarantee seats in parliament - the secularist Republican People's Party (CHP) polled 20%, and the right-wing Nationalist Action Party (MHP) 14%.
Estimates said the CHP would win up to 112 seats and the MHP some 70 seats, with up to 27 going to independent candidates, including pro-Kurdish politicians.
The election was touted as one of the most important in Turkey's history and turnout was reported to be extremely high, with many people breaking off holidays to return home to vote.
The key test now, says the BBC's Sarah Rainsford in Ankara, will be who the party puts forward for president and whether or not it is willing to compromise.
At AKP headquarters on election night the crowd was calling for Foreign Minister Abdullah Gul to become president, but it was his nomination that sparked this whole crisis in the first place.
He is a devout Muslim and his wife wears the Islamic headscarf.
It is not clear how the staunchly secularist military will react to the re-election of the AKP.
During the deadlock over the presidency, the army said it was prepared to step in to defend Turkey's secular system.
The current president, Ahmet Necdet Sezer, and the secularist establishment have vowed to resist what they regard as the Islamist agenda of the AKP.
Mr Erdogan's government dismisses that portrayal, pointing to its record of five years of economic growth and the start of membership negotiations with the EU.
And, our correspondent says, with this massive of vote of confidence in the AKP, almost half of the population have turned out to show they do not believe it is any threat to Turkey's secular system.
With such a clear mandate, the AKP may be tempted to nominate Abdullah Gul again, she says, though most believe the party will look for consensus to avoid dragging the country back into chaos.