Robert Walter Sewell was born on November 20, 1950, in Independence, Missouri, and moved to Texas with his parents at the age of twelve. He has lived in Texas since, attending Thomas Jefferson High School in Port Arthur and Lamar University in Beaumont, where he received a bachelor's degree in biology. He went on to the University of Texas Medical Branch at Galveston, where he achieved his medical degree in 1974. He was accepted into the general surgery residency program at the University of Texas Health Science Center in San Antonio and completed his surgical training in 1979.

After finishing his residency, Dr. Sewell immediately began his surgical practice in the Mid-Cities between Dallas and Fort Worth in North Texas. He moved his practice to its current location in Southlake, Texas, in 2003, and remains an active surgeon today, with an emphasis on minimally invasive general surgery at the Texas Health Harris Methodist Hospital Southlake.

As a recognized specialist in the field of laparoscopic surgery, Dr. Sewell has lectured on various minimally invasive procedures throughout the United States and around the world. He is a member of the American Society of General Surgeons (ASGS) and was elected president of that organization in February 2008. He is also a fellow of the American College of Surgeons (FACS) and has served as a governor since 2013. Dr. Sewell maintains memberships in the Association of American Physicians and Surgeons, the Texas Medical Association, the Tarrant County Medical Society, as well as the prestigious Texas Surgical Society.

Along with his wife, Donna, Dr. Sewell resides in Colleyville, Texas, where he enjoys golf, photography, computer graphics, video production, gardening and, of course, writing.