Mr de Blasio told reporters that his optimism reflected the success of a massive drive to get New Yorkers vaccinated.
He said 6.4 million doses of vaccine have been administered in the city of more than 8 million residents.
"We are ready to bring New York City back fully on July 1," Mr de Blasio told a news briefing. "Now we can see that light at the end of the tunnel."
Mr de Blasio said he had not discussed the city's reopening date with Governor Andrew Cuomo but his announcement comes a day after the governor lifted restrictions that would clear the way for a revival of the city's nightlife.
The state has the power to impose or lift restrictions on restaurants and other venues.
"I think the best way to proceed here is to set out the city's vision," Mr de Blasio said.
While he acknowledged the city needed to make more progress on vaccinations, he said more than 70 per cent of New Yorkers have had at least one dose of a coronavirus vaccine.
"People are showing up," he said. "We need to keep the momentum going," he added. "This is exactly how we get to the full reopening we're all looking forward to."
Coronavirus cases, hospitalisations and deaths have trended lower in New York City since the beginning of the year.
On a seven-day rolling average, the city reported over 7,000 new cases a day at the outbreak's peak in January.
By March new infections ebbed to 4,000 a day and now average about 2,000 a day.