Bradley, 53, had been facing mounting pressure to keep his position despite having three years to run on his contract after the Americans underperformed as hosts of last month's CONCACAF Gold Cup, where they lost to Mexico in the final.
"We want to thank Bob Bradley for his service and dedication to U.S. Soccer during the past five years," U.S. Soccer President Sunil Gulati said in a statement.
"During his time as the head coach of our men's national team he led the team to a number of accomplishments, but we felt now was the right time for us to make a change."
Bradley, whose son Michael is a member of the national team, took over as the permanent head coach in 2007 after being taken on as interim coach when the U.S. flopped at the 2006 World Cup in Germany.
He enjoyed instant success, winning the 2007 CONCACAF Gold Cup at home and leading the U.S. to the final of the 2009 Confederations Cup in South Africa.
He then safely guided the team through the qualifiers for the 2010 World Cup, also in South Africa, but the U.S. lost in the second round to Ghana after drawing with England in the group stage.
Bradley was linked with a move to Aston Villa but signed a four-year extension last year to stay on as U.S. head coach.
However, his position came under renewed attack after the U.S. were beaten by Panama in the group stages at last month's CONCACAF Gold Cup. They recovered to reach the final against Mexico, but squandered a 2-0 lead to lose 4-2.
"It is always hard to make these decisions, especially when it involves someone we respect as much as Bob," Gulati said. "We wish him the best in his future endeavours."
There was no immediate announcement on who would replace Bradley but Gulati said he would make another announcement on Friday, leading to speculation that a successor had already been decided.
A handful of coaches have been linked with the job, including former Germany World Cup winner and coach Jurgen Klinsmann.
Klinsmann said last year he had agreed to a financial package to take over from Bradley before talks broke down over how much control he would have.
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