Mark Edward Diamond, born on April 12, 1955, in Bethlehem, Pennsylvania, passed away on October 30, 2026, at New York Presbyterian Hospital.

He was the beloved son of the late Eugene and Betty (Schiffer) Diamond and the cherished brother of Harriet Shamis. He is also survived by his nephews, Eric Shamis and his wife, Stacy, and Brandon Shamis; his great-nephews, Benji and Bryan; and many dear friends who will miss him.

Mark grew up in Bethlehem and graduated from Liberty High School. He went on to attend Binghamton University, where he earned a Bachelor of Arts degree in History and in Literature and Creative Writing, graduating with honors and earning membership in Phi Beta Kappa. He subsequently received his law degree from New York University School of Law.

Mark enjoyed a distinguished career spanning legal publishing, court administration, consulting, professional training, and real estate. From 1980 to 2000, he held several editorial leadership positions at Matthew Bender, a division of LexisNexis, including Managing Editor and Executive Editor of its bankruptcy law publishing group. In these roles, he supervised editorial teams and oversaw numerous legal publications, collaborating with leading attorneys, professors, and judges. His work included contributions to the respected legal treatise Collier on Bankruptcy, as well as legal software and professional newsletters.

From 2001 through 2012, Mark served as Operations Manager for the United States Bankruptcy Court for the Southern District of New York. In this capacity, he oversaw court policies, procedures, and compliance across three divisional offices, advised judges and court staff, and helped implement significant changes resulting from the Bankruptcy Abuse Prevention and Consumer Protection Act of 2005. He also developed training materials, drafted court rules and procedures, and coordinated with other courts and legal professionals. His dedication and expertise made meaningful contributions to the administration of bankruptcy practice.

From 2013 to 2015, Mark continued to share his extensive knowledge and experience through Mark Diamond Consulting & Training. As a consultant and trainer, he helped attorneys, claims agents, and other bankruptcy professionals navigate federal bankruptcy law and procedures.

In 2015, Mark embarked on a new professional chapter as a Licensed Associate Real Estate Broker with Douglas Elliman Real Estate, serving the New York City metropolitan area through 2021. Specializing in Manhattan residential sales and rentals, particularly cooperatives and condominiums, he brought together his legal and business expertise with his lifelong appreciation for architecture and design.

Throughout his career, Mark also enjoyed consulting and training in team management and professional development. He valued strong leadership, clear communication, and high standards, bringing thoughtfulness, practical knowledge, and dedication to every endeavor.

Beyond his professional accomplishments, Mark found great pleasure in life's simple joys and maintained a wide range of personal interests. He loved antiquing, browsing thrift stores, and exploring garage sales, especially when accompanied by his sister Harriet. He had a particular appreciation for the Arts and Crafts design movement and admired the architecture of Frank Lloyd Wright. From his parents, he developed a lasting appreciation for fine textiles and fabrics. He also valued the arts and remained interested in the world around him.

Mark was deeply committed to social justice and consumer advocacy, causes that reflected his sense of fairness and concern for others. He was also a devoted and supportive friend, maintaining many meaningful friendships throughout his life.

He maintained an active lifestyle, swimming and riding his stationary bicycle daily. He particularly cherished his annual trips to Provincetown, Massachusetts, a favorite destination that became a beloved tradition.

Mark was a lifelong member of Congregation Brith Sholom in Bethlehem. For the past 35 years, Congregation Beit Simchat Torah in New York City had also been his spiritual home, providing another important source of community and connection.

Mark will be remembered for his intelligence, curiosity, dedication, professional accomplishments, commitment to his values, love of family and friends, and appreciation for life's everyday pleasures. He will be deeply missed by all who knew him.

Services: A graveside service will be held at 11 A.M on Wednesday, November 4, 2026, at Brith Sholom Cemetery, 1435 Graham Street, Fountain Hill, PA 18015.  The funeral procession will gather at 10:15 A.M. at the Cantelmi Funeral Home, 1311 Broadway Fountain Hill, PA 18015 before proceeding to the cemetery.Mark's arrangements have been entrusted to Cantelmi Long Funeral Home, Bethlehem. A memory tribute may be placed at www.cantelmifuneralhome.com.

Contributions: In lieu of flowers, contributions in Mark's memory may be made to either of the two congregations that held a special place in his life: Congregation Beit Simchat Torah, 130 West 30th Street, New York, NY 10001 or Congregation Brith Sholom, 1190 West Macada Road, Bethlehem, PA 18017.