William Sumner Appleton Jr. (May 29, 1874 – November 24, 1947) was founder of the Society for the Preservation of New England Antiquities (SPNEA) in 1910.

[3] He was educated at Hopkinson's School for Boys, Boston, and graduated from Harvard College in 1896.

[4] Appleton worked tirelessly to promote preservation of buildings from the 17th, 18th, and early 19th centuries.

He focused on buildings that were aesthetically pleasing, had historic significance, and could be independently supported.

When he died in 1947, the SPNEA had grown tremendously and remains a strong and active organization today.