All year, Adelaide Fringe organisers have had their fingers crossed for this: the festival has become the first in Australia to sell a million tickets.

They nearly didn't make it.

The Fringe hit the milestone at 10.01pm on Sunday, the final night of the 31-day event, with 1,000,916 tickets sold.

The festival includes cabaret, theatre, comedy, circus, music and visual arts, and of the $25.2 million box office take, just under $24 million will go to artists and venues.

"Selling one million tickets in a national first at any event or festival is an accolade that South Australians can proudly claim," Adelaide Fringe director Heather Croall said.

As an open-access festival where anyone can stage an event, there have been complaints that with 1250 shows on the bill, big-name artists have monopolised audiences while newer acts struggled to sell tickets.

But the average event sold just under 43 per cent of seats according to organisers, a figure that's well above other similar festivals internationally.

The festival is still about one-third of the size of the famed Edinburgh Fringe, held in a city less than half the size of Adelaide.

More than three million people attended the 2023 program including free events.