The protest – organised by Destiny Church's Freedom and Rights Coalition – started at Onepoto Domain about 11am today.
The harbour bridge was closed for 90 minutes as about 2000 people walked across the bridge chanting "mandates gone by 1st of March" and "freedom".
The decision to let protesters walk across the bridge came even though the protest was known about last week and followed police speaking with protesters this morning.
A police spokesman said officers "actively engaged with the protest organisers this morning to deter them from unlawfully crossing the Auckland Harbour Bridge".
The march then went ahead.
The spokesman said: "In order to avoid escalating the situation and thus creating further significant safety risks to the public, police closely monitored the group as they walked along the two outside lanes of the Harbour Bridge and all southbound lanes were closed in order to manage safety risks."
Protesters unfurled a giant anti-mandate banner on the bridge, fixed onto a clip-on rail.
All protesters were off the bridge by 12.45pm, with the crowd gathered at Victoria Park in the city.
At 1.30pm, Waka Kotahi/NZ Transport Agency said all southbound lanes of the Auckland Harbour Bridge had reopened.
Auckland mayor Phil Goff criticised any plans for protest action to impact on the lives of others.
In a statement to the Herald, Goff said: "The right to protest is a fundamental and valued part of democratic society. That does not, however, give anyone protesting the right to consider themselves above the law.
"The role of the police is to uphold the law. Though they have independence to determine how they respond operationally to any breaches, I would expect the police to respond strongly to any action that puts lives, safety, or property at risk.
"Any protest that needlessly and significantly disrupts the lives of others both invites a police response and will fail to win sympathy from the wider public for its views."
