Major Fontaness was born in Texas. Major Fontaness attended the University of Northampton, in the United Kingdom, from 2006- 2010, graduating with a Bachelor of Law in English Law and Master of Art in International Relations. He attended Officer Candidate School in 2008 apart of the 10 week Platoon Leaders Class. He commissioned into the Marine Corps in July 2010. Second Lieutenant Fontaness attended The Basic School from March 2011-September 2011. After being selected as a Logistics Officer, he was issued orders to 2d Medical Battalion, and served as the Maintenance Management Officer.
In June 2012 Second Lieutenant Fontaness was selected as an Individual Augment to the Police Advisor Team- Detachment Musa Qala in support of Operation Enduring Freedom. First Lieutenant Fontaness was promoted in July 2012. He deployed from November 2012- June 2013, he conducted multiple joint patrols and ran a joint operation center with Afghanistan National Police and Army.
In May 2014 First Lieutenant Fontaness was assigned to Headquarters Company, 6th Marine Regiment as the Regimental Motor Transport Officer. In December 2014 Captain Fontaness was promoted. In May 2015 Captain Fontaness was assigned as the Command Element S-4 Alpha, Special Purpose Marine Air Ground Task Force-Crisis Response-Africa 15.2. During this time, he served as the Assistant Officer-in-Charge of the Full Mission Profile- Embassy Reinforcement for U.S. Embassy Bamako, Mali.
In January 2016 Captain Fontaness volunteered to be a combat replacement for the S-4 Officer, Battalion Landing Team 2/6, 26th Marine Expeditionary Unit. He reported to BLT 2/6 while it was underway in the Persian Gulf. In March 2016 Captain Fontaness planned the amphibious landing and sustainment of Task Force Spartan into Firebase Bell, Iraq in support of Operation Inherent Resolve.
In September 2016 Captain Fontaness was a hotfill for Officer Selection Officer Raleigh East, 4th Marine Corps District. While serving as the Officer Selection Officer, every year Captain Fontaness met and exceeded his mission and contracted 151 Candidates. He was the 4th Marine Corps District Rookie of the Year, top female candidate recruiter, and heavy hitter.
In July 2019 Captain Fontaness received orders to Combat Logistics Battalion 3 and was assigned the Transportation Services Company Commander. During his tour he led his Marines through a focused maintenance program where the company’s readiness increased from 38 percent to 80 percent in 100 days. In July 2020 he was assigned the Combat Logistics Detachment 331 Officer-in-Charge for Bougainville II exercise in support of 3rd Battalion, 3rd Marines.
In August 2020 Captain Fontaness was assigned to Marine Corps Forces Pacific as a War Plans Logistics Planner. Major Fontaness was promoted in September 2020. He was a lead planner in the Marine Corps Prepositioning Program – Pacific and Pacific Fury 202.
In July 2022 Major Fontaness was assigned to Combat Logistics Battalion 22 as the Operations Officer. He deployed in July 2023 part of the Logistics Combat Element of the 26th Marine Expeditionary Unit (Special Operations Capable). Upon his return from the deployment he was assigned as the Executive Officer for the battalion in May 2024.