The 2009 Sony Ericsson Open was a men's and women's tennis tournament held from March 23 to April 5, 2009. It was the 25th edition of the Miami Masters event and was played on outdoor hard courts at the Tennis Center at Crandon Park in Key Biscayne, Florida, located near Miami. The tournament was part of 2009 ATP World Tour and 2009 WTA Tour, classified as ATP World Tour Masters 1000 and Premier Mandatory event respectively.