Rafal Trzaskowski from Tusk's Civic Coalition was defeated by conservative historian Karol Nawrocki in the June 1 runoff vote, unleashing recriminations from the smaller partners in the coalition government and casting doubt over the administration's future when a hostile president is able to wield veto powers.
MPs voted 243-210 in favour of the government.
There were no abstentions.
Tusk's broad coalition has 242 MPs in the 460-seat lower house, or Sejm, meaning it was always likely to survive Wednesday's vote of confidence.
"I needed this vote because we were seeing ... speculation that this government will not make it, that Tusk may be taken down, and you cannot work under such conditions," Tusk said.
However, he added that he still needed to regain voters' confidence: "We need to do much more."
In a debate ahead of the vote, Tusk listed higher defence spending and a cut in visa issuance for migrants as major achievements since he took power in December 2023, replacing the nationalist Law and Justice party (PiS), which backs Nawrocki.
Tusk also said his government would continue its efforts to roll back judicial reforms implemented by PiS that the European Union says undermine the courts' independence.
Poland's outgoing president, Andrzej Duda, also a PiS ally, has so far blocked the government's attempts to reverse the judicial reforms.
Analysts say many Polish voters are disillusioned with the government's failure to deliver on promises including reforming the judiciary and raising the threshold at which Poles start paying taxes.
In an interview published on Wednesday, president-elect Nawrocki told Dziennik Gazeta Prawna daily that he would sign a law to raise the tax-allowance threshold and would even submit such a bill himself if the government did not.
In an apparent swipe at the government's failure to implement the 100 promises it made for its first 100 days, Nawrocki said he would "do (them) for Donald Tusk. Isn't that conciliatory?".
The government had hoped for a Trzaskowski victory in the presidential election that would have given it the freedom to fully implement its agenda.
Facing questions about his leadership even from normally sympathetic media outlets, Tusk framed the vote of confidence as a chance to relaunch his 18-month-old government.
"I would like you to know that for the entire ... coalition, this is to be a day of new momentum and I am convinced that you will live up to this task," he told his government ahead of Wednesday's vote.
Tusk has said there will soon be a government reshuffle, probably in July.
with AP
