Plummer E. Jefferis (December 27, 1851 – June 6, 1925) was an American politician from Pennsylvania.

Plummer E. Jefferis was born on December 27, 1851, in Brandywine Hundred, New Castle County, Delaware.

[1] He built the school building on South High Street, Friends' School in North Ward, the Episcopal Tower, West Chester Ice Plant and houses in West Chester, Pennsylvania.

He supervised the construction of the Williamson Free School of Mechanical Trades near Elwyn, Pennsylvania.

He was a member of the board of trustees of Dime Savings Bank of Chester County.