David Thomas Williams is an emergency medicine practitioner and business person. He founded MedFast Urgent Care Centers and currently serves as its President and Chief Medical Officer. MedFast Urgent Care Center’s is the largest and fastest growing urgent care provider on the central coast of Florida. 11 centers are located in Brevard and Volusia counties. MedFast cares for over 100,000 patients and receives over 10 million dollars in revenue annually. In 2000, Williams joined Wuesthoff Health Systems as chairman of the emergency medicine department. He founded several private emergency medicine practices, including MedFast Urgent Care Centers in 2007.
According to Williams, he showed an interest in the outdoors at an early age. While attending California University of Pennsylvania, Williams spent his summers working for the helitack emergency team at Yellowstone National Park. There he became certified in helicopter rescue and participated in the park's first heli-rappel rescue. After graduating with a Bachelors degree in biology in 1987, Williams attended medical school at the Philadelphia College of Osteopathic Medicine. He earned a doctorate in osteopathic medicine in 1991 and completed a residency at the University of Florida Health Science Center. He began playing Rugby competitively in college at age nineteen. In 2005 he was one of four players to travel to Cuba for a competition.
Military and NASA career
During his residency, Williams was awarded a military medical scholarship. He attended the Naval Aerospace Medical Institute, where he graduated in 1993. Afterwards he served with the U.S. Marine Corp. for three years as a flight surgeon for F-18 squadrons in Hawaii and served two deployments in Southeast Asia. Williams also created a Medivac plan used by 10,000 military staff participating in the annual Cobra Gold military exercise.  Williams developed Medivac procedures used in the annual U.S. military exercise Cobra Gold and a neurological rating scale as a tool for NASA to evaluate whether an astronaut is ready to return to space.
In 1996, Williams received a medical clerkship with NASA at the Johnston Space Center. There he developed a neurological rating scale used as a tool by NASA to evaluate whether astronauts are ready to return to space.  He also earned a medical certification from NASA and the Department of Defense in order to work in the aerospace industry.
Williams returned to his residency at the University of Florida Health Science Center before taking a sabbatical to take a temporary position in Star City, Russia with a NASA sub-contractor. There he served as a mission operations physician for the Mir space shuttle program.  Williams managed a clinic that monitored the health of astronauts and their families and helped train astronauts in conducting medical procedures aboard the space shuttle. Williams also created emergency medical and evacuation procedures for NASA's staff.
Williams applied to be a NASA astronaut in 1997, but dropped his application after learning that it often takes years to be considered.
David Williams completed his residency in emergency medicine at the University of Florida Medical Center before taking a position at the Hollywood Medical Center in 1999. In July 2000, he accepted a position as the chairman of the emergency medicine department of Wuesthoff Health Systems. Williams founded two private medical practices in Rockledge and Melbourne, before opening the first MedFast Urgent Care center in 2007.  MedFast has since then grown to eleven urgent care centers in Brevard and Volusia counties. Williams also provided medical aid to victims of the 2010 Haiti Earthquake, as part of a medical relief team.
David Williams served NASA as a support physician at the Kennedy Space Center in Florida. He has also been a lieutenant commander in the Naval Reserve and served as the medical director for the Florida Medical Training Institute. He is the EMS medical director for Cape Canaveral Air Force Station, and the cities of Titusville, Cocoa and Rockledge. David Williams completed the North American Wild Sheep Grand Slam of Hunting on March 13, 2019. He completed the hunting accomplishment after chasing the four hardest hunt challenges in North America. He obtained the final ram, a Desert Bighorn Ram, in the Mexican subalpine desert. The ram is an all-time Boone and Crockett record scoring 183 3/8.