Wynnewood is a suburban unincorporated community, west of Philadelphia, that straddles Lower Merion Township, Montgomery County and Haverford Township, Delaware County, Pennsylvania, United States. It was named in 1691 for Dr. Thomas Wynne, William Penn's physician and the first Speaker of the Pennsylvania General Assembly. Lower Merion Township is the fifth-most-affluent town in the United States. Wynnewood is one of many neighborhoods on the historic Pennsylvania Main Line, and is the home of institutions such as Lankenau Hospital, St. Charles Borromeo Seminary, Palmer Theological Seminary, and Friends' Central School.