Amber Murray Mathwig (b. 1982), of Arlington, Minnestota, served as a master-at-arms in the United States Navy from 2002-2012.

Amber Murray Mathwig was born 12 April 1982 in Arlington, Minnesota. In high school she considered joining the military and took Armed Services Vocational Aptitude Battery (ASVAB), but it wasn't until after the September 11 attacks in 2001 that she decided to enlist. She filled out an online recruiting form and six weeks later she was contacted by a United States Navy recruiter.

At the Military Entrance Processing Station in St. Paul, Minnesota, Mathwig chose law enforcement as her Naval Enlistment Classification (NEC), and left for Naval Station Great Lakes, Illinois, on 20 May 2002. From July to October of 2002, Mathwig attended Master-At-Arms school at Lackland Air Force Base San Antonio, Texas, for specialized law enforcement duty and weapons training. In November 2002, Mathwig was deployed to United States Fleet Activities Sasebo, Japan, where she worked twelve hour shifts, fifteen days a month, standing post and calling dispatch.

After about a year in Japan, the Navy Medical Corps sent Mathwig to rehabilitation for alcohol abuse at Commander Fleet Activities Yokosuka, Japan. When she adamantly denied having an alcohol problem, Mathwig was asked to leave the facility, which she knew meant that she would be processed for separation from the U.S. Navy.

When Mathwig returned to Sasebo, she requested a Captain's Mast (non-judicial punishment disciplinary hearing) to inquire about obtaining a recommendation to remain in the military despite her rehabilitation failure, but was approved for separation in February 2005. When she met with her Command Master Chief, he assisted in attaining a waiver for her to be able to stay in the U.S. Navy.

Mathwig then received orders to Naval Base San Diego, California, where she worked in the training department enforcing regulations and also attended firearm instructor school. She was selected as an Individual Augmentee for temporary duty assignment, and attended pre-deployment training in South Carolina.

In October 2008, Mathwig deployed to Task Force 134 at Camp Victory in Baghdad, Iraq, where she mainly performed administrative work. After Iraq, Mathwig returned to Lackland Air Force Base for brigade school training. By this time she had decided to become a limited duty officer, and chose a sea duty billet.

In June 2009, she arrived at Naval Station Norfolk, Virginia, and was certified as an official instructor. In May 2010, Mathwig attended a training exercise to prepare for the deployment of the USS Kearsarge in August. For the first year of deployment, as part of law enforcement, Mathwig felt the need to remain separate from the other crew, all the while becoming increasingly frustrated with the long work hours and the amount of pressure being put on her. She was prescribed antidepressants, but was no longer allowed to carry firearms and was subsequently relieved from her security position in December of 2010.

She then began work in the legal department. In 2011, Mathwig submitted forms to remain in the U.S. Navy, but she was denied the opportunity. In 2018, Mathwig earned a graduate degree in Women and Gender Studies at the University of North Carolina at Greensboro.