The polling from GB News was carried out after Queen Elizabeth II's death last week.
It found that 63 percent of respondents were in favour of keeping the monarchy, while just 19 percent opted for an elected head of state.
The People's Poll also returned good results for King Charles III, as 57 percent had a favourable opinion of the new monarch.
And his mother, Queen Elizabeth II, received an outpouring of emotion as 74 percent of Brits think her legacy is good for the country.
King Charles III paying his respects to his late mother, Queen Elizabeth II
POOL
Queen Elizabeth II is lying in state in Westminster Hall
Yui Mok
Many respondents were yet to make up their mind about the new King, with 20 percent choosing "don't know" or "prefer not to say".
Meanwhile, new Prime Minister Liz Truss is yet to receive any sign of a polling bounce as the level of support for the Conservative Party has not changed.
It comes as thousands of mourners visit London to pay their respects to Queen Elizabeth II.
A queue of people almost three miles long started moving gradually forward on Wednesday as well-wishers saw the monarch lying-in-state from 5pm.
The line has the capacity to stretch for 10 miles, but there is no guarantee that everyone who joins it will get to file past the coffin.
Regardless, people turned out in their droves for the opportunity to say a personal farewell ahead of the funeral on Monday.
Numbers will be monitored towards the end of the lying in state period, which must be completed by 6.30am on Monday.
Entry to the line will be paused if the queuing infrastructure – stretching 6.9 miles from Victoria Tower Gardens to Southwark Park, with a further three miles in the park itself – reaches capacity.
There will be more than 1,000 volunteers, stewards, marshals and police officers on hand at any one time as people brave the wait on the banks of the Thames.
They include 779 professional stewards per shift, assisted by 100 civil service volunteer marshals, 40 adult scouts, and 30 members of the First Aid Nursing Yeomanry charity, as well as Metropolitan Police officers.