Beating all predictions, Wednesday's exit poll put Wilders' Freedom Party (PVV) at 35 out of 150 seats, 10 seats ahead of the closest rival, former EU Commissioner Frans Timmermans' Labour/Green Left combination. That margin was far greater than expected and appeared to be too great for the outcome to change.
Exit polls are generally reliable with a margin of error of roughly two seats.
At a cafe in The Hague, Wilders fans erupted in cheers, hugged and threw their arms in the air.
In a victory speech, Wilders vowed to bring an end to a "tsunami of asylum and immigration."
Wilders' rode a wave of anti-immigration sentiment, blaming a housing shortage on flows of asylum seekers and drawing on widespread concerns about the cost of living and the overburdened healthcare system.
The 60-year-old's upset victory came two months after the return to power of the equally anti-European Union populist Robert Fico in Slovakia, who pledged to halt military aid to Ukraine and cut immigration.
Last year, Italy formed its most right-wing government since World War 2 after the election victory of Giorgia Meloni.
Wilders' inflammatory views on Islam have prompted death threats and he has lived under heavy police protection for years.
Abroad, his outspoken comments about the prophet Mohammed led to sometimes violent protests in nations with large Muslim populations, including Pakistan, Indonesia and Egypt. In Pakistan, a religious leader issued a fatwa against him.
A self-proclaimed fan of Hungary's Victor Orban, Wilders is also explicitly anti-EU, urging the Netherlands to control borders, to significantly reduce its payments to the union and to block the entrance of any new members.
He has also repeatedly said the Netherlands should stop providing arms to Ukraine, saying it needs the weapons to be able to defend itself. However, none of the parties he could potentially form a government with share these ideas.
The party of outgoing Prime Minister Mark Rutte, the conservative VVD, was in third place at 24 seats, the exit poll showed.
Immigration - the issue that triggered the collapse of Rutte's last cabinet after 13 years in power - has been a key issue in the campaign.
Wilders is expected to try to form a right-wing government with the VVD and the upstart party 'New Social Contract', who together would hold a 79-seat majority.
Talks could be difficult as both parties have said they have serious doubts about working with Wilders, because of his outspoken anti-Islam stance, which includes aiming to ban all mosques and Korans from the Netherlands.
"I am confident we can reach an agreement," Wilders said in his victory speech. "I understand perfectly well we should not take any measures that would be unconstitutional."
His party had now become too large to ignore, he said, adding he was ready to lead the country.
Wilders is internationally known for his anti-Islam politics and was convicted by a Dutch judge for discrimination after he insulted Moroccans at a campaign rally in 2014.
Rutte will remain in a caretaker role until a new government is installed, likely in the first half of 2024.
