William James Duggleby (March 16, 1874 – August 30, 1944), nicknamed "Frosty Bill", was an American pitcher for the Philadelphia Phillies.

Duggleby and Ed Murphy pitched for the Auburn Maroons in the New York State League in 1897 and were sold to the Phillies that December.

As of 2011[update], he still holds the Phillies team record for hit batsmen for a career (82).

The Phillies filed suit to prevent the "jumpers" — in particular, Nap Lajoie, Bill Bernhard, and Chick Fraser — from playing for any other team, a plea which was rejected by a lower court before being upheld by the Pennsylvania Supreme Court.

He was the manager of the Minor League Baseball team, the Albany Babies, in 1912.