The NFL selects five nominees for the award each week and fans vote for the winner on NFL.com. More than 83,000 fans voted for this week's award.
The other nominees this week were Cleveland WR Andre Davis, Green Bay S Marques Anderson, Denver RB Clinton Portis and New Orleans WR Donte Stallworth.
McMichael was recognized after catching five passes for 79 yards and a touchdown in the 30-3 victory over the New York Jets.
Running back Ricky Williams, meanwhile, didn't have quite as much luck when it came to the AFC Offensive Player of the Week award. The NFL chooses the nominees and winners for this honor, and Williams was among the nominees this week.
But he was beaten out by Cleveland quarterback Tim Couch, who led the Browns to a 31-28 overtime victory over the Tennessee Titans.
Former Dolphins linebacker Larry Izzo, now with New England, was this week's winner of the AFC Special Teams Player of the Week award.