William H. Seely III is a major general in the United States Marine Corps who has served as commandant of the Dwight D. Eisenhower School for National Security and Resource Strategy since July 2023.

In June 2024 he was named as the next commandant of the Virginia Tech Corps of Cadets.

In 1995, he graduated from the United States Army Military Intelligence Officer Advanced Course.

In 2002, he graduated from United States Marine Corps Command and Staff College, Non-Resident Course (JPME-1).

Jun 2016 - May 2017 - Director of Marine Corps Intelligence 2017 - 2019 - Marine Corps Director of Communication 2019 - 2020 - Commander, Task Force-Iraq (TF-Iraq), CJTF - Operation Inherent Resolve Aug 2020 - Aug 2021 - Commandant of the Joint Forces Staff College (JFSC) Aug 2021–Present - Director of Marine Corps Intelligence