Moira Quirk was born on March 6, 1968, in Queens, New York, making her the third of six siblings. Her father, Peter, was a classically trained violinist, while her mother, Anne, was a dedicated nurse. Both parents hailed from Ireland, having immigrated to the United States. Growing up in Ronkonkoma, New York, Moira spent her formative years in a loving family environment.
Moira's educational journey began at Connetquot Senior High School, where she graduated in the class of 1986. Her academic pursuits continued at Marymount Manhattan College. Little did she know, her high school days would also mark the beginning of her illustrious acting career.
In 1984, Moira landed a small role in Connetquot Senior High School's production of Annie. However, due to illness, the original actress playing Miss Hannigan was forced to withdraw from the production. Director Eric Martinsen took the opportunity to recast Moira as Grace Farrell, a decision that would prove to be a turning point in her life. Moira's remarkable performance as Grace not only earned her critical acclaim but also marked the start of her professional acting career.