William B. Fitzgerald Sr. (February 3, 1914 – December 7, 1970) was a Michigan politician.

Fitzgerald was born on February 3, 1914, in Troy, New York.

[1] On November 7, 1978, Fitzgerald was elected to the Michigan House of Representatives where he represented the 4th district from January 13, 1965, until his death in office on December 7, 1970.

[1] Fitzgerald had two children, including fellow state representative William B. Fitzgerald Jr. William B. Fitzgerald's brother, George S. Fitzgerald, was also a state legislator.

Fitzgerald was Catholic.