It also pushed back the National Day Rally, another major event at which the prime minister addresses the nation, by a week to August 29.
Singapore reverted to Phase 2 (heightened alert) on Thursday amid a spike in COVID-19 cases. Group sizes for social gatherings have been reduced from five to two and dining-in has been suspended.
The restrictions will be in effect until August 18. The Ministry of Health (MOH) said earlier this week that the government will review the measures in two weeks.
Singapore reported 170 new COVID-19 cases on Thursday.
In a press release, the Ministry of Defence (MINDEF) said the National Day Parade (NDP) ''will be similar to the one held last year at the Padang, but will take place at the Float@Marina Bay''.
Padang has been the most popular open field for holding national events in the city centre of Singapore while Float@Marina Bay is a floating platform venue in waters off Padang for major events.
Fireworks in the heartland, satellite towns of public housing out of the city, and Red Lions displays previously announced to be held over the August 7-8 weekend will be cancelled, the MINDEF said.
Red Lions is free-falling by armed forces' parachuters over several parts of Singapore.
The NDP rehearsal and preview, previously planned for July 24 and July 31, have also been postponed, according to a report by Channel News Asia.
''To prepare for the NDP on Aug 21, rehearsals will be conducted later in smaller component groups,'' the MINDEF said, adding that the dates will not be announced so as to discourage crowds from gathering around Marina Bay.
''Since 1966, the NDP has been held every year to mark Singapore's independence (on August 9),'' it said.
Spectators at this year's parade would have to undergo pre-event testing and be vaccinated against COVID-19.
Following the postponement of the National Day Parade, the Prime Minister's Office announced that the National Day Rally will be pushed back by a week to August 29.
There are currently 28 active clusters in Singapore with infections ranging between three and 560.
Five more cases have been linked to the Marina Bay Sands Casino cluster, bringing the total number of infections to 15. The hotel-based casino is an international resort in the city centre.
The overall number of new cases in the community has increased from 127 in the week before to 883 in the past week.
As of Thursday, Singapore had reported a total of 63,791 coronavirus cases while 36 people had died from virus-related complications.
''We are likely to continue to see a high number of cases in the coming days as we step up efforts to detect them to contain their spread in the community,'' Channel News Asia quoted the MOH as saying.
Currently, there are 415 cases in hospital wards, with most well and under observation. There are currently seven cases of serious illness requiring oxygen supplementation, and one in critical condition in the intensive care unit. None among these eight cases is fully vaccinated, the MOH said.
Over 4.18 million people in Singapore have received at least one dose of the COVID-19 vaccine while 2.84 million people have completed the full vaccine regimen, it said.