James Holmes joined the Tufts University men's basketball staff in the summer of 2023. In his first season as top assistant, Holmes led the Jumbos to a 21-8 overall record, including a Sweet 16 appearance in the NCAA tournament. The Jumbos finished the season ranked 14^th in the country. Holmes also helped develop Sophomore Scott Gyimesi to NESCAC First Team All-Conference Honors, as well as NABC/D3hoops.com All-Region Honors.
 
Holmes joined the Jumbo staff after serving as an assistant coach at Rensselaer Polytechnic Institute in Troy, NY for the previous two seasons. During his time at RPI, Holmes helped the Engineers to 42 wins including an appearance in the Sweet 16 in the 2022 NCAA Tournament. He also was part of the 2022 Liberty League Coaching Staff of the Year after helping the squad finish the year ranked No. 21 in the D3hoops.com poll. 

Prior to his time at RPI, Holmes was was an assistant for two seasons at Oswego State in Oswego, NY, where he helped the Lakers to a NCAA Sweet 16 appearance in 2019 along with a SUNYAC title. Holmes also had a two-year stint as a graduate assistant and student assistant at his alma mater SUNY Oneonta. In addition to his coaching appointments, he has experience working camps at Columbia University, Yale University, University of Virginia, Dartmouth College, Skidmore College, University of Rochester and the University of Albany. 

Holmes earned a bachelor's degree in history in 2016 and a Master's in school counseling in 2018, both from Oneonta.

A graduate of Shaker High School, where he played basketball and baseball, he comes from a family lineage of basketball coaches. His father, Jeff, coached the boys' varsity team at Shaker for more than 25 years; his uncle, Steve Holmes, was a college coach at SUNY Geneseo and Salisbury University in the 1990s-2000s; and his grandfather, Ray Holmes, was a long-time high school boys' coach in the Plattsburgh and Potsdam areas. Also an athletic administrator, Ray Holmes is a member of multiple Athletic Halls of Fame.