About 100 males, many wearing masks, approached the pub in Wembley, near where the stadium where the match was held, and assaulted customers in the beer garden, police said.
"While a number of the group were wearing England hats and scarves, it is believed they were German 'fans'," a police statement said.
"The group entered the beer garden of the pub and began assaulting customers, most of whom were in the area to attend the England vs Germany match. Punches and projectiles including traffic cones were thrown.
"Officers responded and the group fled. The disorder lasted for around two minutes."
The police said "a number of people" sustained head and facial injuries, with three suffering serious leg, wrist and thumb injuries. Four people were arrested.
"None of those injured are believed to be in a life-threatening condition," the statement added.
