Demetries Grimes was born in Indianapolis, Indiana. He served in the U.S. Navy from 1990 to 2017. Grimes received his bachelor's degree from Boston University in 1987. He attended the Joint Military Attaché School in 2006 and undertook Naval War College Postgraduate Studies from 2008 to 2010. He received his executive M.B.A. from the London Business School in 2017. He retired as a commander in the United States Navy. He served as a naval officer, naval aviation, diplomat (in Greece and Israel), and Secretary of Defense fellow. Grimes has been affiliated with the Society of White House Military Aides, the American Legion, Veterans of Foreign Wars, and the Republican Party. He was a Republican candidate for a US House seat from Florida in 2018, Grimes ran in a special election to the Florida House of Representatives to represent District 35. He will not appear on the ballot for the special Republican primary on November 7, 2023.