Bryn Mawr (/ˌbrɪnˈmɑːr/, from Welsh for 'big hill') is a census-designated place (CDP) located in Pennsylvania, United States.

Bryn Mawr is located toward the center of what is known as the Main Line, a group of affluent Philadelphia suburban villages stretching from the city limits to Malvern.

They became home to sprawling country estates belonging to Philadelphia's wealthiest families during the Gilded Age, and over the decades became a bastion of old money.

Bryn Mawr is named after an estate near Dolgellau in Wales that belonged to Rowland Ellis, a Welsh Quaker who emigrated in 1686 to Pennsylvania to escape religious persecution.

[3][4] Until the construction of the Pennsylvania Railroad's Main Line in 1869, the town, located in the old Welsh Tract, was known as Humphreysville, named for early settlers of the Humphreys family.

After a fire destroyed the original building, a distinctive new hotel designed by architect Frank Furness was built in 1889.

[15] According to the U.S. Census Bureau, in 2000, Bryn Mawr had a total area of 0.6 square miles (1.6 km2), all land, all in Lower Merion Township in Montgomery County.

As a result, the geographic term Bryn Mawr is often used in a sense that includes not only the CDP, but also other areas that share the ZIP Code.