Mrs May was greeted with cries of "coward" and "shame on you" as she returned to the site of the devastating fire in west London on Friday.
Hundreds of protesters also marched on Whitehall, central London, to voice their frustration at the Government's response to the fire, which ripped through the tower block in north Kensington on Wednesday morning. The queen waved to the crowd, and then hesitated before getting into her auto.
Labour Party leader Jeremy Corbyn, meanwhile, also visited St. Clements Church on Thursday and was photographed hugging local residents.
On Friday angry protesters chanting "We want justice" stormed their way into the Kensington and Chelsea town hall to try to confront the leaders of the local council. But reports on 16 June said that some Grenfell residents would be rehoused "outside the area".
This is an absolutely very bad fire that took place.More news: Fowler back in the thick of it at US Open
London Mayor Sadiq Khan said people were frustrated by the lack of information about the missing and the dead as well as a lack of coordination between support services.
Following the meeting, May released a strongly-worded statement in which she said on-the-ground support for families in the immediate aftermath of the blaze "was not good enough".
It followed a separate, smaller protest at Kensington Town Hall, where residents tried to air their grievances to councillors. The building had been home to a diverse group of residents, many of them from Sudan, Eritrea and Syria.
Inside the sports center, which has become a major hub for the relief effort and a shelter for those displaced in the fire, the queen and prince met volunteers and emergency services. London police expect the death toll to rise further but said it could take months to search the burned-out building and identify the victims.
May, whose political position was already weakened by a poor showing in parliamentary elections last week, announced the government would immediately provide 5 million pounds ($6.39 million, 5.7 million euros) to help victims of the fire. But we may well need help from our close neighbours.