Liberal Leader Kevin Vickers is stepping aside after failing to win a seat in the legislature.
Vickers lost to People's Alliance candidate Michelle Conroy by nearly 1,300 votes in the Miramichi riding.
Conroy was re-elected with 45.1 per cent of the vote, compared with 28.6 per cent for Vickers.
"It's time for another leader to step up and take the party forward," Vickers said after his personal loss and the party's defeat in the provincial election at the hands of the Progressive Conservartives.
WATCH | Kevin Vickers says he will step down as Liberal leader
He said the people of New Brunswick have spoken and he respects "the decision of our citizens."
Vickers said he stood by his decision not to agree to Premier Blaine Higgs's conditions for avoiding a snap election. He said Higgs didn't have the mandate to "act on those initiatives."
"For the good of democracy, it was the right thing to do," said Vickers.
When asked if there was a future for him in politics, Vickers said "never say never."
He also said there may be other ways to contribute.
"I look forward to those challenges," said Vickers.
Vickers, who turns 64 later this month, was a political newcomer when he announced his candidacy early last year.
He had been riding a wave of popularity after being hailed as a national hero for helping to end the 2014 attack on Parliament Hill by a lone gunman.
On Oct. 22, 2014, Vickers was serving as sergeant-at-arms of the House of Commons when he fired the shots that killed a man armed with a .30-30 rifle. Michael Zihaf Bibeau had barged into Centre Block on Parliament Hill after killing honour guard reservist Cpl. Nathan Cirillo at the National War Memorial.
Vickers was appointed ambassador to Ireland by then-prime minister Stephen Harper in January 2015.
Although born and raised in the Miramichi, Vickers spent most of his adult life living outside New Brunswick, something political pundits speculated may work against him.
Liberals lost five seats
The Liberals lost five ridings that they won in 2018 — Moncton East, Moncton South, Carleton-Victoria, Fredericton North and Saint John Harbour — and roughly three per cent of the popular vote.
But they did manage to win back the north-eastern riding of Shippagan-Lamèque-Miscou to complete the sweep of the north, as predicted.
The popular vote for the Liberals dropped to 34.41 per cent from 37.8 per cent in 2018. That compares to 39.48 per cent for the PCs this time around — up from 31.9 in 2018.
New Brunswick Votes 2020 Results: Watch returns come in live on our interactive results page.