 Poindexter was born in Odon, Indiana, the son of Ellen (Sommers) and Marlan G. Poindexter.He received his undergraduate degree from the United States Naval Academy in 1958, where he graduated first in a class of 899.His fellow graduates included astronaut Bruce McCandless II (who graduated second) and Senator John McCain; previous National Security Advisor Robert McFarlane was a contemporary, graduating the following year.