Nicastro, Peter James , age 50, of Chesterfield, MO, passed away on March 9, 2026, fortified with the Blessed Sacrament, surrounded by his loving family and friends.

Peter is survived by his beloved wife, Ellen Nicastro; his dearest children, Peter, Jr. and Elizabeth; his devoted mother, Mary Elizabeth Nicastro; his loyal brother Charles (Monica) Nicastro Jr.; numerous cousins, aunts, uncles, nieces and nephews.

Many will say that Peter left this world after a lifelong battle with cystic fibrosis, but anyone who truly knows him is aware that he was never defined by or limited by his medical problems.  He lived despite his cystic fibrosis.  Everyone knew him for his intelligence and kindness, and he will be deeply missed.

Peter was born on April 28, growing up in Overland and Florissant, MO.  He attended Hazelwood Central High School, graduating as valedictorian of his class.  He went on to earn his undergraduate degree at Saint Louis University.  He then started to work on his MD/PhD at Northwestern University, but his lungs had other ideas resulting in a premature return home for a lung transplant. Eventually, he returned to school for his master's in biology at University of Missouri - St. Louis and his MBA through Washington University. Peter married the love of his life, Ellen, on August 2, 2003.  Together, they built an incredible life, cherishing each and every day.  They lived through many hardships and medical miracles, ultimately raising their fierce twins, Peter Jr and Elizabeth.  Each day they spent as a nuclear family and with extended family and friends was always a gift.  Not a day was wasted.  Peter always had a list of all the free stuff to do, and they did it all.

Peter was employed at Pfizer from 1998 through 2010 as a biochemist and then moved to Express Scripts/Cigna to work as finance director.  Despite his busy careers and crazy kids, he found so many other ways to make his mark on our world.  He was active in the Knights of Columbus, joining at age 18, and serving in many roles, including Grand Knight of Bishop Wurm Council 1376, Faithful Navigator of the St. Louis Assembly, and various Missouri state director positions.  He was appointed to the Missouri Organ Donor Advisory Committee, serving as chair for 4 years, and was instrumental in adding a checkbox to state tax forms to donate to the organ donor fund.  Finally he found time to be active with his son in Boy Scouts, volunteering as den leader and assistant cubmaster for Cub Scout Pack 623, as well as being the most knowledgeable Advancement Chair for Boy Scout Troop 371.

Above all, Peter made a difference in so many ways that cannot be accounted for in one obituary.  But his motto to get him through is something we can all aspire to - Do better today.  We might not always be able to put forth our best, but we can always do something a little bit better than the day before.  And for Peter, may perpetual light shine upon him.  Until we meet again in paradise.

In lieu of flowers, Peter and his family would prefer donations be made to Mid-America Transplant Foundation, 1110 Highlands Plaza Dr. East, Suite #100, St. Louis, MO 63110.  You may donate online at www.midamericatransplant.org/get-involved/make-a-contribution/ .

Furthermore, if you have not done so already, please consider signing up to be an organ donor.

Services: Visitation at the SCHRADER Funeral Home and Crematory, 14960 Manchester Road at Holloway, Ballwin, Sunday, March 15, 2026 from 3:00 - 8:00 p.m.  Funeral Mass at Ascension Catholic Church, Chesterfield, Monday, March 16, 2026 at 10:00 a.m. Interment PRIVATE. Friends may sign the family's on-line guestbook at Schrader.com.