Shane O'Neill

Colorado Rapids

O'Neill joined the U.S. Soccer Development Academy with the Colorado Rapids youth system in 2009. He led the Rapids U18 team in scoring in 2011–12 with 10 goals in 15 games, helping them reach the playoffs. O'Neill originally signed to play college soccer at the University of Virginia, however on June 19, 2012, O'Neill signed with the Colorado Rapids as a homegrown player. Three months later, he made his professional debut in a 3–0 victory over the Portland Timbers, coming on as an 86th-minute substitute for Jeff Larentowicz. O'Neill became a regular starter in 2013 and received strong reviews, earning the Rapids' Young Player of the Year award and a nomination for U.S. Soccer Young Athlete of the Year as the Rapids returned to the playoffs. His first career goal came in a 4–1 home win over Montreal Impact on May 25, 2014.

Apollon Limassol

On August 7, 2015, O'Neill was bought by Cypriot club Apollon Limassol for an undisclosed fee. On August 31, 2015, he was loaned out to Royal Mouscron-Péruwelz in Belgium. The loan was cut short on December 23, 2015, and he returned to Limassol having not made an appearance for the Belgian club. He had subsequent loan spells with League 2 side Cambridge United and NAC Breda in Jupiler League, never featuring for Apollon Limassol.

Excelsior

O'Neill joined Excelsior on a one-year deal for the 2017–18 season.

Orlando City

In June 2018, O'Neill returned to MLS when he signed a…

O'Neill is eligible to represent both the United States and the Republic of Ireland. On October 9, 2012, O'Neill was called up by the United States U20 national team for the 2012 Marbella Cup in Spain. A day later, O'Neill made his debut for the U20s in a 2–1 loss to Canada, however he suffered an eye injury that ruled him out for the rest of the tournament. He later played for the U.S. at the 2013 FIFA U-20 World Cup. He has yet to debut for the U.S. senior team and has indicated a willingness to accept a call for his native Ireland. He participated in a U.S. camp in January 2014, although he was dropped prior to a friendly against South Korea. He was called up to the United States senior squad for a friendly against Panama in February 2015.

As of match played March 29, 2025

O'Neill is the son of former All-Ireland winning Cork Gaelic footballer, Colm O'Neill, and is a nephew of former Kerry Gaelic footballer, Maurice Fitzgerald. O'Neill is the younger brother of Darragh O'Neill, a former punter for Colorado Buffaloes football team. He is the older brother of Vancouver Whitecaps defender Mark O'Neill. His cousin Ronan Teahan is a fellow professional footballer. O'Neill's family immigrated to the United States from Ireland when he was a toddler after his father won a green card through the Diversity Immigrant Visa lottery program. O'Neill grew up in Boulder, Colorado and attended Fairview High School. In his senior year of high school, O'Neill was named the Colorado's player of the year by Gatorade and selected to the All-Colorado boys soccer team. O'Neill played basketball in high school and was named to the second-team all-5A team for his performances during his senior year. Although he committed to the University of Virginia, O'Neill ultimately signed with his hometown team the Colorado Rapids at the age of 18.