"I've spoken to a number of people around the province over the last couple of weeks and they have encouraged me to stay on as leader because we have a heck of a lot of work to do," she said Wednesday in her first news conference since the election.
Horwath triggered the election by declaring she couldn't support the minority Liberal government's budget.
The Liberals ended up winning a majority of seats, robbing the NDP of the balance of power in the legislature that they've held since 2011.
The NDP won 21 seats, unchanged from their standing before the election. They made gains in northern Ontario, but lost three important seats in vote-rich Toronto to the Liberals.
Horwath said she has no regrets about the campaign, which raised the ire of some party supporters who said she'd had lost her way with populist policies and her rejection of a left-leaning budget.
Voters didn't reject the NDP's platform, she said. They just parked their votes with the Liberals because they were scared of a Progressive Conservative government that would make major cuts to government spending.
"The people of this province, they made a decision to basically choose fear or to vote out of fear as opposed to choose positive change," she said.
"That's their decision to make. That means we have a lot of work to do around the strategic voting issue and we're going to get down to doing that work."
Her newly elected caucus will also work to hold the Liberals to account, she said.
The Liberals will be re-introducing a "Trojan-horse" budget that they're spinning as a progressive spending plan, Horwath said.
"But scratch below the surface and it's clear this regressive budget will negatively affect Ontario and Ontarians," she added.
"Ontarians voted against austerity in this election and New Democrats will be there to speak out against a regressive budget that sells off valuable public assets, that continues huge corporate tax loopholes and leaves families paying more."
Premier Kathleen Wynne is signalling that she's serious about slaying Ontario's $12.5-billion deficit in three years, appointing deputy premier Deb Matthews as Treasury Board president to keep a tight grip on the province's purse strings.
New Democrat Percy Hatfield, who easily reclaimed his seat of Windsor-Tecumseh, says he still supports Horwath "absolutely 100 per cent" and doesn't regret his party's decision to trigger the election.
But it "remains to be seen" how the NDP will affect change now that they have no way of twisting the Liberals' arm, he said before heading into a NDP caucus meeting to discuss the election.
Asked for his opinion of the party's election strategy, Hatfield responded: "I don't have one right now."
Many people were nervous about Tory Leader Tim Hudak's promise to cut 100,000 public sector jobs to help eliminate the deficit a year ahead of the Liberals, Hatfield said.
"Is that fear or is that bad campaign policy? I don't know."
The Liberals won 58 seats in the election, while the Tories got 28 — down from 37 before the election was called.