The American midfielder, who grew up in South Florida, joins from college team Georgetown University in Washington, D.C, where he played a major role in the side that won its first NCAA National Championship in 2019.
During Georgetown's championship campaign, Montes co-led his team in scoring with 11 goals, five assists, and recognition as Big East Conference Midfielder of the Year.
Having represented the United States national team at the Under-19 level, Montes also played for Portland Timbers USL reserves, Portland Timbers Academy, FC Florida U23 and FC Florida Prep Academy.
Having put pen to paper, Montes said: “I’m extremely excited. It’s been a dream to be a professional soccer player since I could walk, really, so to be able to sign for a Premier League club is incredible.
“I want to try to make a good impression, and do whatever I can to perform at the highest level.”
Chairman Steve Parish said: “We’ve been really impressed by Jacob, and welcome him to the club.”