Mark William Ryan, 65, of Chevy Chase, MD, passed away from complications following heart surgery on Monday, November 30, 2020. Mark was born October 6, 1955, in Batavia, New York, to Michael and Ellen Ryan. As the oldest son and third child of seven, his values were shaped by an Irish Catholic upbringing in a small western New York town. When asked about his childhood, Mark loved to wax poetic about his summers on his family’s dairy farm, which was established in 1885. His parents imparted to him the importance of education. Mark’s father, Mike, was a graduate of Cornell University, a stockbroker, and an original founder and board member of Genesee Community College. Each of his mother Ellen’s seven paternal aunts attended college and six became teachers. Ellen, a graduate of SUNY Cortland, also became a teacher. Mark was a Phi Beta Kappa graduate of Syracuse University, earning a Bachelor of Arts in 1977. He served two terms as president of Syracuse’s student judicial board. After Mark’s graduation from college, friends and family knew that his true aptitude was in the power of persuasion. Mark said of himself, “Even before going to law school, I knew that I wanted to be a litigator.” In 1981, Mark received his J.D. from Duke University School of Law. After law school he joined Mayer Brown’s Washington, D.C. office, and distinguished himself as litigator. In addition to being a top lawyer, Mark was a leader. At Mayer Brown, he served as the Partner in Charge of the Washington, D.C. office, a leader of the global litigation practice, and most recently, as the head of the Firm’s Global Antitrust & Competition group. Because of his reputation as an exceptional trial lawyer, the US Justice Department’s Antitrust Division created a new position just for Mark, the Director of Litigation, responsible for the Division’s most important cases. Mark’s fondest accomplishment was his successful litigation, as lead trial lawyer, on behalf of the United States in the Apple e-books price-fixing trial. In addition to his work, Mark enjoyed spending time with his wife Nancy and his three children, Maryellen, Molly, and Jimmy. He proposed to Nancy at the Plaza Hotel in New York on the day he made partner. Mark and Nancy married in 1988 and their marriage spanned three decades. They settled down in Chevy Chase in the mid-1990s, where they developed a large community of friends through their neighborhood and children’s schools. Mark’s devotion to his career and his passion for the law inspired his three children to select careers which reflected their passions and afforded them the opportunity to serve others. He was impressed with Maryellen’s work on causes she came to champion, like supporting survivors of violence and addiction at diverse organizations including both the Universities of Maryland and Michigan. He thought she had a true talent for this work and was proud that she is pursuing a master’s degree at the University of Chicago in social administration and social welfare policy. Mark was touched that Molly followed in the footsteps of his mother in the teaching profession; she is currently teaching first grade in New York City, after completing her master’s degree in education at the University of Pennsylvania in 2018. Mark and Jimmy shared a mutual love of competition, whether on the field or in the courtroom, fostering in Jimmy the desire to pursue playing and coaching at the collegiate level. He enjoyed watching Jimmy’s successful lacrosse seasons at Ithaca College, his climb up the coaching ladder, and his recent promotion to assistant lacrosse coach and defensive coordinator at Rutgers University. Frankly, Mark’s success as a trial lawyer can be traced to his passionate disposition for debate, which he inherited from both parents. He honed his craft in his childhood home on his brothers and sisters, and tried to continue the practice with his nuclear family. Nancy sometimes gently reminded Mark that his wife and children were not his opposing counsels or witnesses on the stand. This summer was the occasion of numerous, loud, fiery political debates often held in the swimming pool at his beloved beach house. Imagine Mark’s surprise, yet secret joy, that some students in his home, particularly Molly, could best him. A lover of music, Mark was often one of the first on the dance floor. Nancy sometimes told people he was an erratic but eager dancer. He loved to loudly play and sing classic rock music, especially from the artists Bob Dylan and Bruce Springsteen. It is well known that he often bellowed an off-key version of Don McLean’s “American Pie.” Mark often could be found supporting his many favorite teams, including the Syracuse Orange and his beloved Buffalo Bills. Despite the perpetual disappointment that comes with being a Bills fan, Mark never ceased to express optimism for their upcoming season. Every year he and his mother, Ellen, made plans to attend the upcoming Super Bowl when the Bills would finally win the last game. His family feels that he and his mother, who passed away in February, are in heaven eating wings and cheering for the successful season Buffalo is having. Mark left us unexpectedly; however, his family is struck by the sheer number of people from all parts of his life who have expressed sympathy upon his passing. The outpouring of stories and memories shared are remarkably similar in that they all reflect his sharp mind, his sense of humor, and most of all, his authentic character. He will be missed. The term “Irish Exit” was invented for Mark Ryan. When it is safe, we will hold a huge, raucous, celebratory party in honor of Mark’s life. We will see all of you there. Mark is survived by his wife Nancy Allison Ryan, his children Maryellen (Scott Estrada), Molly, and Jimmy, siblings Elizabeth, Ann, Joseph, Thomas, John, and Daniel (Colleen) Ryan, in-laws Kay Allison, Mary Allison (Tommy Wiles), Mickey Allison (Kelly Long), and Bobby Allison, his nephew Seamus Ryan (Judy Rath), his aunt Nancy McCarthy, and other aunts, uncles, nieces, nephews and cousins too numerous to name. Private Mass of Christian Burial will be celebrated at the Shrine of the Most Blessed Sacrament, Washington, DC. Interment Private. In lieu of flowers, memorial contributions may be made to the Greg Gannon Canned Food Drive at www.ggcfd.org or to Beebe Medical Foundation, 902 Savannah Rd., Lewes, DE 19958. All are welcome to join the live stream of Mark's Funeral Mass on Saturday, December 5, at 11 a.m. - please visit the tribute wall page of this obituary for the link.