Sergeant Major Peter A. Siaw currently serves as the Command Senior Enlisted Leader, Marine Corps Combat Development Command / Sergeant Major, Combat Development & Integration.
Prior to his appointment on 11 July 2025, he served as the Command Senior Enlisted Leader, I Marine Expeditionary Force; Command Senior Enlisted Leader, Training and Education Command; Command Senior Enlisted Leader, 3d Marine Aircraft Wing; Command Senior Enlisted Leader, Marine Corps Installations Pacific – Marine Corps Base Camp Smedley D. Butler; Command Senior Enlisted Leader, Education Command / Marine Corps University; Sergeant Major, Recruit Training Regiment, Marine Corps Recruit Depot (MCRD) San Diego; Sergeant Major, 2d Recruit Training Battalion, MCRD San Diego; Sergeant Major, 1st Light Armored Reconnaissance Battalion; and Sergeant Major, Marine All-Weather Fighter Attack Squadron 121. He was promoted to his current rank in October 2007.
Sergeant Major Siaw enlisted in the United States Marine Corps and began his service at Marine Corps Recruit Depot (MCRD) San Diego, California in April 1993. Since then, he has served in the Fleet Marine Forces with I, II, and III Marine Expeditionary Forces as well as Marine Forces Reserve in the following units: Marine Air Control Squadron 6 (November 1993 – June 1997); Marine Aircraft Group 12 (September 2001– April 2004); 1st Battalion 3d Marines (April 2004 – September 2006); Military Police Company, Twin Cities, Minnesota (September 2006 – November 2007); Marine All-Weather Fighter Attack Squadron 121 (December 2007 – September 2009); 1st Light Armored Reconnaissance Battalion (September 2009 – February 2011); and 3d Marine Aircraft Wing (April 2018 – July 2020); I Marine Expeditionary Force (April 2022 – July 2025).
He has also served in the Supporting Establishment with Training and Education Command and Marine Corps Installations Command in the following units: 2d Recruit Training Battalion (June 1997 – September 2001); 2d Recruit Training Battalion (February 2011 – April 2012); Recruit Training Regiment (April 2012 – February 2014); Education Command / Marine Corps University (March 2014 – January 2016); and Marine Corps Installations Pacific – Marine Corps Base Camp Smedley D. Butler (February 2016 – April 2018).
Sergeant Major Siaw’s Combat History includes: Operation Iraqi Freedom (Al Fajr/Phantom Fury) - Battalion Landing Team 1/3, 31st Marine Expeditionary Unit (July 2004 – May 2005); Operation Enduring Freedom - 1st Battalion 3d Marines (January – May 2006); and Operation Enduring Freedom - 1st Light Armored Reconnaissance Battalion (May – November 2010).
He has attended numerous Professional Military Education (PME) courses, including Amphibious Warfare School Phase I and II (Non-Resident), Senior Enlisted Joint PME I and II, the Keystone Course (Class 16-2), and the Senior Executives Asia-Pacific Orientation Course. He holds a Bachelor of Arts degree in Management with a Concentration in Leadership.
Sergeant Major Siaw's personal awards include the Legion of Merit (gold star in lieu of fifth award), the Bronze Star Medal, the Meritorious Service Medal (gold star in lieu of third award), the Navy and Marine Corps Commendation Medal (gold star in lieu of second award), the Navy and Marine Corps Achievement Medal (gold star in lieu of third award), and the Combat Action Ribbon (gold star in lieu of second award).