Live southern oyster drills, Stramonita haemastoma floridana (Conrad, 1837), have been collected from two Chesapeake Bay western shore tributaries. Four specimens were collected be- tween Brown Shoal and Thomas Rock in the lower James River in February 2005. Thirteen live southern oyster drills were collected from Back River in April 2006. Identification of these drills as Stramonita haemastoma floridana has been confirmed using DNA bar-coding data. Southern oyster drills collected in Chesapeake Bay are genetically nearly identical to populations from the Atlantic coast, and differ significantly from popula- tions from the Azores and from the Gulf of Mexico. These collections mark the first reported records of live southern oys- ter drills from within the Chesapeake Bay estuary. It is un- known if these drills represent isolated introductions or expan- sions of the northern range this species. Water temperature patterns in Chesapeake Bay and the Mid-Atlantic Bight from 1990–2005 are similar to those observed in the late 1950s when Stramonita haemastoma floridana was first found living in Chincoteague Bay, Maryland. Additional Keywords: Range extension, water temperature, Cape Hatteras, zoogeography, DNA bar-coding