Bill Gates’s father was named William H. Gates Sr., so his first name was William. The elder Gates was a prominent Seattle attorney and civic leader whose career shaped the family’s public profile.
William H. Gates Sr. was born in 1925 and became a founding partner of the Seattle law firm Preston Gates & Ellis. He was also active in charitable and community organizations, including work connected with the University of Washington.
People sometimes confuse the father’s name with Bill Gates’s own full name, William Henry Gates III. The “Sr.” designation belongs to the father, while the younger Gates used “III” because he shared the family name across generations.