Some 872 people crossed on 15 small vessels, according to the latest provisional Government data.
Firgues suggest an average of around 58 people per boat.
The cumulative number of arrivals by small boats in 2023 now stands at a provisional total of 20,973.
On August 10, the previous high for the year was set when 756 people made crossings .
The total for the year so far is still lower than this time last year, when 25,000 people had already made the journey.
The record high for a single day since current records began in 2018 is still 1,295 on August 22, 2022.
Saturday’s arrivals mean 1,172 people made the journey so far this week after 300 migrants arrived on Tuesday. Crossings were seen on just two out of six days.
Pictures from the Channel show increasingly precarious boats being sent into one of the world’s most dangerous shipping lanes as human smugglers continue to show a disregard for life.
Dozens of people are packed into one tiny dinghy as they sit on the sides, back and front of the boat, many with their legs dangling in the sea.
Labour accuse Prime Minister Rishi Sunak - who vowed to stop the boats of failing to get a grip on Channel crossings.
On Monday, Home Secretary Suella Braverman told Sky News the Home Office is looking “at all options” to tackle immigration as she refused to rule out electronically tagging those who arrive to avoid costly detention.
Figures will be published on Monday for any crossings which took place on Sunday.
Total arrivals last year were 45,774, compared with the previously documented 45,755, according to the latest available Home Office data.
It comes after the average number of migrants crossing the Channel per boat hit a new monthly high in August, when some 5,369 people made the journey in in 102 boats – an average of around 53 migrants per vessel.
This was the highest monthly average since records began in 2018, according to analysis of provisional Government data.
A Home Office spokesperson said: “The unacceptable number of people risking their lives by making these dangerous crossings is placing an unprecedented strain on our asylum system.
“Our priority is to stop the boats, and our Small Boats Operational Command is working alongside our French partners and other agencies to disrupt the people smugglers.
“The government is going even further through our Illegal Migration Act which will mean that people arriving in the UK illegally are detained and promptly removed to their country of origin or a safe third country.”