Junior Gormley left his home in
Prince Edward Island at the age of 14 to compete with the
Athol Murray College of Notre Dame's hockey program in
Wilcox, Saskatchewan. He played two years of
midget hockey with the Notre Dame Hounds in the
Saskatchewan Midget AAA Hockey League. In 2007–08, he scored 23 goals, and 53 points over 42 games as a 16-year-old, after which the
Moncton Wildcats made him the first overall selection in the 2008
Quebec Major Junior Hockey League (QMJHL) Draft. He joined the Wildcats in
2008–09 and scored 7 goals and 27 points for Moncton in 62 games. His efforts earned him QMJHL All-Rookie Team honours. He improved to 9 goals and 43 points for the Wildcats in
2009–10 and added 17 more points in the playoffs, the third-highest post-season total among league defencemen. Gormley and the Wildcats won the
President's Cup as QMJHL champions, earning a berth in the
2010 Memorial Cup. He scored three points in three games in the national tournament, but the Wildcats lost all three games and were eliminated. Individually, he was voted the recipient of the
Mike Bossy Trophy in 2010 as the Quebec League's top professional prospect. Gormley finished the season highly rated for the
2010 NHL entry draft. The
NHL Central Scouting Bureau listed him sixth among North American skaters, while the International Scouting Services listed him third among all skaters. Scouts described Gormley as "well rounded, but not dynamic" and praised his intelligence on the ice and ability to move the puck. Gormley went on to be selected 13th overall by the
Phoenix Coyotes. He attended his first NHL training camp in September 2010 before being returned to the Wildcats. Playing in his third QMJHL season, Gormley recorded 13 goals and 48 points over 47 games; he was named to the QMJHL Second All-Star Team for the second consecutive year. He added an assist over five post-season games as the Wildcats were eliminated in the first round of the QMJHL playoffs, failing to defend their league title. With his junior season over, the Coyotes assigned him to their
American Hockey League (AHL) affiliate, the
San Antonio Rampage. He played in four AHL games, recording an assist. In his fourth season with the Wildcats, Gormley played 26 games before being traded to complete his junior career with the
Shawinigan Cataractes hours before the January 7, 2012, QMJHL trade deadline.
Professional Gormley was assigned to the Coyotes' new AHL affiliate, the
Portland Pirates, to begin his first full professional season in
2012–13 season. He appeared in 68 games with the Pirates and ranked second among the blueline with 24 assists and 29 points. In the second year of his entry-level contract, Gormley remained with the Pirates, quickly assuming leadership responsibilities to be selected as an Alternate Captain for the
2013–14 season. Gormley was used heavily in all situations with the Pirates and was placing 8th in the AHL in scoring amongst blueliners, before he received his first NHL recall by Phoenix on March 7, 2014. He made his NHL debut on March 10, 2014, against the
Tampa Bay Lightning. Gormley featured in 5 games with the Coyotes going scoreless before he was returned to Portland to finish the season with new career offensive highs all across the board. Approaching the final year of his rookie contract with the Coyotes, Gormley failed to establish a first-team position and was familiarly reassigned to the Portland Pirates to begin the
2014–15 season. During his first recall of the season to Arizona, Gormley scored his first NHL goal on November 16, 2014, against
Ben Scrivens of the
Edmonton Oilers. With the Coyotes languishing in the standings, Gormley was recalled on several occasions throughout the season, and although given opportunity failed to cement a regular position among the defense corps. He finished the season appearing in a career-high 27 games for 4 points. On July 31, 2015, Gormley was re-signed by the Coyotes to a one-year, two-way contract. Unable to develop as the Coyotes had hoped and with his eligibility to waivers, Gormely was traded by Arizona to the Colorado Avalanche in exchange for the rights to restricted-free agent
Stefan Elliott on September 9, 2015. Gormley made the Avalanche roster to begin the
2015–16 season, making his debut with Colorado in a 1–0 overtime defeat to the
Carolina Hurricanes on October 21, 2015. Used in a depth role, Gormley recorded his first point with the Avs in his 22nd game, registering an assist in a 3–1 victory over the
St. Louis Blues on December 13, 2015. Unable to secure a position on the blueline, Gormley was placed on waivers by the Avalanche on January 7, 2016. After going unclaimed, he was later assigned to former AHL club, the San Antonio Rampage, on January 13, 2016. Gormley remained with the Rampage until the season closed, and on June 27, 2016, he was not offered a new contract from the Avalanche, releasing him to free agency. On July 28, 2016, Gormley was signed as a free agent to a one-year, two-way contract with the
New Jersey Devils. In the
2016–17 season, Gormley cleared waivers and was assigned to add leadership to the blueline of AHL affiliate, the
Albany Devils. Gormley contributed with 2 goals and 10 points in 35 games before he was traded by the New Jersey Devils to the
Ottawa Senators for future considerations on March 6, 2017. Acquired to help out the AHL's Binghamton Senators, Gormley was dealt following the trade deadline, making him ineligible for a recall to Ottawa. Having left the Senators familiarly as a free agent in the off-season, Gormley went un-signed over the summer. On September 25, 2017, he agreed to an AHL invite to attend the
Toronto Marlies 2017 training camp. Following his release from the Marlies, Gormley opted to accept a European offer, signing a one-year deal with Swedish outfit,
Mora IK of the SHL, on October 16, 2017. After two seasons with
Frölunda HC in the SHL, Gormley became a free agent. After going unsigned throughout the summer of 2020, he belatedly signed a contract with the
Straubing Tigers of the
Deutsche Eishockey Liga (DEL) on December 21, 2020. In the following
2020–21 season, Gormley increased his scoring output from the blueline in Germany, contributing with 3 goals and 17 points in 34 regular season games. At the conclusion of his contract with Straubing, Gormley continued his journeyman career, signing a one-year contract with Latvian-based club,
Dinamo Riga of the KHL, on August 19, 2021. In December, Dinamo traded him to
Lokomotiv Yaroslavl, where he played out the remainder of the season, and contributing with 1 assist in three playoff contests. As a free agent, Gormley opted to continue his tenure in the KHL by agreeing to a one-year contract with
HC Sochi on August 15, 2022. Having concluded his contract with Sochi, Gormley left the club after a lone season and returned to the German DEL, in agreeing to a one-year contract with the Iserlohn Roosters on October 2, 2023. Gormley started the 2024-25 season without a contract but, on October 18, 2024, he agreed to return to Iserlohn for another season. ==International play==