No Millwall fans were present, but the figure is the lowest attendance to watch a league game at Leeds since just 14,459 turned up for the visit of Oldham Athletic in May 1989.
It was also the lowest gate for an opening day crowd in 44 years.
"We had an open day last week and there was thousands here," explained Kevin Blackwell.
"I was saying `see you next week' but everyone said they were on holiday because I think it's Leeds' main holiday week this week.
"It's early in the season and a lot of crowds were down yesterday and a lot of people are still on holiday at this time of year.
"It is Leeds' biggest week for holidays, but all we can do is play football. This is a massively-supported club and it will be - it's a long old season."