William Francis McNulty (born August 29, 1946) is an American retired professional baseball player.

The Sacramento Union named him to the All-City team as a third baseman in 1964, his senior year,[2] in which he had a .355 batting average with six home runs.

[4] That year, McNulty enlisted in the United States Marine Corps Reserve, attending boot camp for six months.

[6] On July 9, 1969, Tommie Reynolds went on the disabled list with a broken finger and the Athletics promoted McNulty to the major leagues.

The Athletics purchased McNulty's contract back from Milwaukee before the start of the season and returned him to Iowa.

[10] After the 1971 season, the Athletics traded McNulty and Frank Fernández to the Chicago Cubs for Adrian Garrett.

[10] Having too many outfielders and wanting to prioritize the development of Terry Hughes as a third baseman, the Cubs loaned McNulty to the Brewers for the 1972 season.

[4] McNulty's father drove to Alturas where he found two forest rangers who located Bill at his campsite to tell him that there was a family emergency.

[7] After the 1972 season, the Athletics traded McNulty and a player to be named later to the Texas Rangers for Paul Lindblad.

[7] Before the 1974 season, the Brewers purchased McNulty's contract from the Mets and assigned him to the Sacramento Solons of the PCL.

[24] However, the Brewers attempted to cut his salary, and he signed with the Lotte Orions of Nippon Professional Baseball for $70,000 ($396,364 in current dollar terms) one month into the 1975 season.