The Bundesliga club accepted a penalty imposed on them as punishment for the violence which broke out before and after the pre-season match in the Austrian town of Eugendorf.
More than 20 arrests were made by police who deployed riot officers to quell the disturbances.
Three Leeds supporters, two police officers and two security officials were injured in the violence, none of them seriously.
Fans from Frankfurt clashed with police ahead of the kick-off and fighting raged between rivals supporters after United fans spilled onto the pitch at the end of Frankfurt’s 2-1 win on July 21.
Eintracht’s followers - some of whom were pictured wearing balaclavas - were eventually herded out of the ground as riot police intervened.
In a statement issued today, the German FA said its sport court had imposed the fine of around £15,000 for the “unsportsmanlike conduct” of Frankfurt’s fans.
“The club has agreed to the judgment, the judgment is therefore final,” the statement added.
At the time, Salzburg Police pointed the finger of blame firmly at a group of Eintracht ‘Ultras’ who they accused of causing “substantial problems” on the day of the match.
Pepper spray was used to disperse fans as police officers attempted to main control in the centre of Eugendorf, 10 miles to the north of Salzburg.
The mayor of Eugendorf has since banned the staging of further friendlies in the town.