St. William is a US Catholic parish founded in January 1920 in the Philadelphia Pennsylvania neighborhood of Lawncrest. The parish originally served 70 households. The Parish elementary school was opened in 1924. The parish eventually expanded to include a rectory, convent, kindergarten, lower school, junior high school, day care center, parish hall and the two churches. The school, which reached a peak enrollment of 1,586 students in 1964, closed on June 15 2012 with a final enrollment of 280 students. As of 2013, the church served 1,750 households totaling 4,600 people.