The Owings Mills resident was 74.
Born in Kansas, Mr. Donnelly moved with his family as a toddler to Carroll County, where his father had acquired a family farm.
Mr. Donnelly graduated from Westminster High School and later attended Queen's University in Belfast, Ireland for one year in 1956. He returned to the U.S. and studied at the University of Notre Dame in Indiana, where he became a lifelong fan of " Fighting Irish" football.
Mr. Donnelly left Notre Dame for family reasons and returned to Baltimore, where he earned a bachelor's degree from Loyola College, what is now Loyola University in 1961. In 1964, Mr. Donnelly earned a law degree from the University of Maryland School of Law.
He began practicing law with the firm of Niles, Barton, Gans & Markell, which later become known as Niles, Barton & Wilmer, where he remained until his death. He was a firm partner.
"He was an excellent lawyer," said Mr. Michael Yaggy, a lifelong friend, who also worked at the firm for several years.
According to a family obituary, he helped develop new ways to apply federal grants to restart a steel company in Kentucky that had closed, saving 1,200 jobs. His work in Kentucky earned him the title "Kentucky Colonel" by the state's then-governor, John Y. Brown, his family said. He also helped develop the Knoxville World's Fair.
"He had a very accomplished legal career," said Mr. William C. Trimble Jr., who met Mr. Donnelly in law school and described him as a hard worker.
Mr. Donnelly frequently traveled to Ireland throughout his career. He represented several Irish real estate investor groups that bought property and businesses in the United States. For nearly two decades, he served as director of the board for the Ashford Castle Hotel in Cong, Ireland, and worked as its legal advisor as its owners turned it into what is listed as a luxury 5-star hotel.
Mr. Donnelly, of Irish descent, loved Ireland, his family and colleagues said.
"He was proud of his Irish heritage," Mr. Trimble said, adding that Mr. Donnelly knew a lot of Irish history as well as current affairs, and even remained in touch with family there. "He was very proud to have attended Queen's University" and Notre Dame, Mr. Trimble said.
His family said his affection for Ireland led to his active participation in the Irish-American Endowment For Education and the Dublin City University Educational Trust.
Mr. Donnelly was also dedicated to serving the local community. He was a member of The Bachelors Cotillion, the Maryland Club and the Green Spring Valley Hunt Club, where he had also served as secretary of the board of directors. He served on the boards of the Roland Park Country School and the Odyssey School in Stevenson, where he developed a long-term interest in the students with special needs, Mr. Yaggy said.
Mr. Donnelly himself was an avid reader, reading "a great deal his entire life," everything from history, to business or fiction — a wide-range of topics, Mr. Yaggy said.
Mr. Yaggy, who first met Mr. Donnelly while his father worked on Mr. Yaggy's father's farm in Baltimore County, said they remained friends for 60 years with similar career paths, their early love of hunting, and their families.
Mr. Yaggy said Mr. Donnelly and his wife, the former Chessie Shriver, met at Mr. Yaggy's wedding — the two were in the wedding party. Later, Mr. Yaggy and his wife, Mrs. Nora Yaggy, were in the Donnellys' wedding party. Mr. and Mrs. Donnelly married in 1969.
Mr. Donnelly's love of the outdoors continued throughout his life as he regularly fished, golfed and hunted upland game and waterfowl. He not only hunted locally, but he also took trips as far as Montana, Ireland and a recent trip to Spain to hunt red-legged partridge.
As a teenager, he lost his right eye hunting, but that didn't ruin his love for the sport.
"He would certainly be out shooting every weekend," Mr. Trimble said.
Mr. Donnelly was also described by friends and colleagues as well-liked.
"He was outgoing and loved his fellow man," Mr. Trimble said. "The Cathedral at the Vatican wasn't large enough to hold all of Pat Donnelly's friends," he said.
"He loved life more than anyone I know. He took pleasure in everything he could and would share it with you," said Mr. Yaggy.
In addition to his wife Chessie Shriver Donnelly, Mr. Donnelly is survived by three daughters, Olwyn Donnelly Browne, Meghan Shriver Donnelly, and Melanie Nicholas O'Brien Donnelly; two grandchildren; two sister, Mary Louise Peters and Sheila Donnelly; and two brothers, Daniel Donnelly and Kevin Donnelly.
Services were held at St. Charles Borromeo Church in Pikesville on Sept. 21.