Saint Mary Catholic Preschool 406 Walnut St, Yorkville, IL60560 Located in the St. Patrick Parish Center, Saint Mary Catholic Preschool is Kendall County's only Catholic…More preschool. The school's experienced instructors offer a safe and engaging education environment for children from three through five years-old, emphasizing children's emotional, social, physical, spiritual and intellectual development. The school offers three, four and five day a week classes. Its half day sessions run from 9am to 11:30am and 12:30pm to 3pm, Monday through Friday. Visit the Saint Mary Catholic Preschool website for program, staff and registration information.