Casey has 3 children and lives on the South Shore outside of Boston. He is a die-hard fan of the
Boston Red Sox,
Boston Bruins,
Boston Celtics and
New England Patriots, and participated in the Boston Bruins AT&T Legends Classic hockey game on January 2, 2010. Other participants included
Tim Robbins,
Bobby Farrelly,
Terry O'Reilly, and
Lenny Clarke. Casey scored the winning goal for his team in the second period. In 2009, Casey founded The Claddagh Fund, a charity foundation based on the attributes of the Irish
Claddagh symbolism: "Friendship, Love and Loyalty." It was founded with the help of
Boston Bruins legend
Bobby Orr. In October 2014, Casey, a lifelong
Democrat, announced that he was co-hosting a fundraiser for
Republican gubernatorial candidate
Charlie Baker. Casey stated that "Charlie is a Republican and I'm a Democrat, but I will take a big heart and strong character over political party any day." Casey, who publicly backed Mayor
Marty Walsh's campaign in 2013, also said that Baker helped several of Dropkick Murphys' charitable causes over the years, including supporting military families. Casey is among many Massachusetts Democrats to have supported Baker. On May 20, 2016, Casey and the Dropkick Murphys received the "
Robert F. Kennedy Children's Action Corps' Embracing the Legacy Award" for years of charity work with various organizations including work with children and military veteran. The award, "which parallels Robert F. Kennedy's quest for social justice on behalf of society's most vulnerable people" was presented to the band at the
Kennedy Library. In 2018, Casey was involved in an accident on a building site and suffered severe damage to one of his
vertebral disc which required surgery in May 2018 and caused him to lose feeling in his fingers and forced him to be unable to play the bass during the band's shows until he fully healed. The band was unsure if Casey would be able to begin their 2018 summer tour due to the injury. However, Kevin Rheault, the band's longtime stage tech and who filled in for other band members in the past, filled in on bass at the band's live shows and has since become the band's official bassist on live shows as Casey plays bass only in studio and has since focused on co and lead vocal duties for the band especially with singer
Al Barr on hiatus from the band since 2022. During a St. Patrick's Day show at the House of Blues on March 17, 2019, Casey attempted to defend fans that were being attacked by another concert-goer. He was hit in the head by a beer can, causing blood to appear on his face, though he stayed on stage and finished the concert while the involved fan was escorted from the building. In April 2021, Casey announced that he had returned to college at
UMass to finish up his college degree which he started decades ago. On June 24, 2021, Casey along with music artists
Dionne Warwick,
Sam Moore and
Corey Glover appeared in
Washington DC at the
U.S. Capitol alongside
congressmen Ted Deutch and
Darrell Issa to help introduce the American Music Fairness Act which would help music performers and recorded-music copyright owners to be paid for airplay of their songs on
AM/FM radio stations. The United States currently is the only major country in the world where radio pays no royalties to the performer or copyright owner and only to the songwriter of the song. Casey said, "I'm a punk rocker! We don't even want to be played on the radio, but I'm here in support of my fellow musicians. When other people are making millions and billions, well, I think the trickle down should be a little more equitable." On May 28, 2025, Casey was part of a humanitarian aid convoy visit to
Ukraine. "The band had started to do some T-shirts that were to raise money, 100% of the proceeds go to Ukrainian aid efforts and I just thought it was important to me that if I'm going to be speaking up and asking people to donate money I should actually show up and see things with my own eyes and be a part of it directly" Casey said. Casey appeared on the
Sing for Science podcast on June 12, 2025, where he discussed workers rights with Professor of Practice and Executive Director of the Center for Labor and a Just Economy at
Harvard Law School,
Sharon Block. On September 25, 2025, Casey was honored with the Massachusetts Storyteller of the Year Award by the charitable organization Mass Humanities for a career defined by music, activism, and archival storytelling.
Bet with fan On March 10, 2025, a video from the Dropkick Murphys' March 8, 2025 show in
Clearwater, FL was uploaded by a fan on
TikTok and
Instagram. The video showed Casey stopping the band's show after spotting a fan in the crowd wearing a
President Donald Trump MAGA T-shirt. It has been widely reported for years that despite the President claiming to want to bring more jobs to America, wanting to sell more American made products, his own merchandise for the most part is made in other countries. Casey said, "Dropkick Murphys proudly sells Made in America merchandise only. And here's the bet I'd like to make. If you lose the bet, we switch shirts, ok? If you win the bet, I give you 100 dollars and the shirt." Casey was correct and it was revealed the fan's shirt was not American made and was made in
Nicaragua. The fan lost the bet, removed his shirt and threw it to Casey on stage who gave the fan one of the band's T-shirts. Casey praised the fan for being a good sport, stating, "They were longtime fans who wanted to let us know they disagree with our politics, but they were respectful and after the concert the gentleman actually said, 'Dropkicks are family and I don't let politics come between family,' which I was pleasantly surprised by." According to social media and fans that were at the show, the man who was singled out was not the only person wearing MAGA merchandise. Some others were also wearing
thin blue line pins and
confederate flag pins. Casey said, "I say wear what you like, it's still somewhat of a free country for now...wear a MAGA shirt, dye your hair purple...whatever makes you happy." The video has since received media attention on
Newsweek and has been viewed over 900,000 times on social media. ==Equipment==