More than 500 vehicles set off from Hyde Park to drive the 60 miles to the East Sussex resort in bright autumnal sunshine.
Organisers of the Royal Automobile Club's 77th rally said 572 vehicles were entered to take part in the run this year, although not all managed to make it even over the start line.
To be eligible to enter, cars must be of pre-1905 registration.
A rally spokesman said: "These cars are all over 100 years old so they're not the most reliable and many break down along the way, and there are always a few non-starters."
He said that while some of the larger vehicles could reach speeds of up to 60mph, most were travelling at around 20mph.
One of the first across the start line was a circa 1894 Benz Victoria while a 1904 Darracq, which starred in the 1953 film Genevieve, a comedy about two couples who take part in the rally, was also taking part.
Meanwhile, among those behind the wheel was former Formula One driver Jochen Mass.
The annual rally commemorates the first Emancipation Run in 1896, held to mark the passing of the Locomotives on Highways Act, which raised the speed limit for "light locomotives" from 4mph to 14mph and scrapped the requirement for vehicles to be preceded by a man on foot carrying a red flag.
This year 164 makes were taking part, drivers' ages ranging from 18 to 91.
The spokesman later said that 433 vehicles made it over the finish line in Brighton.
He added: "It's been a brilliant day. The turnout has been absolutely fantastic, I think we've had record crowds.
"There has been a real festival atmosphere, people who were not even taking part turning out in their old cars to support them."