| William Sterling Youngman | |
| Order: | 50th |
| Office: | Lieutenant Governor of Massachusetts |
| Term Start: | 1929 |
| Term End: | 1933 |
| Governor: | Frank G. Allen Joseph B. Ely |
| Predecessor: | Frank G. Allen |
| Successor: | Gaspar G. Bacon |
| Order2: | 42nd |
| Office2: | Treasurer and Receiver-General of Massachusetts |
| Term Start2: | 1925 |
| Term End2: | 1928 |
| Governor2: | Alvan T. Fuller |
| Predecessor2: | James Jackson |
| Office3: | Member of the Massachusetts State Senate Norfolk and Suffolk District |
| Term Start3: | 1923 |
| Term End3: | 1924 |
| Predecessor3: | Wesley E. Monk |
| Birth Date: | February 2, 1872 |
| Birth Place: | Williamsport, Pennsylvania, U.S. |
| Death Date: | April 25, 1934 (aged 62) |
| Death Place: | Brookline, Massachusetts, U.S. |
| Party: | Republican |
| Profession: | Attorney |
| Alma Mater: | Harvard College A.B. 1895; Harvard Law School L.L.B. 1898 |
| Children: | William Sterling Youngman Jr. |
| Branch: | United States Army |
| Serviceyears: | 1898 1918 |
| Rank: | Captain |
| Battles: | Spanish–American War World War I |
William Sterling Youngman (February 2, 1872 – April 25, 1934) was an American politician who served as a Massachusetts State Senator, the Treasurer and Receiver-General of Massachusetts and as the 50th lieutenant governor of Massachusetts from 1929 to 1933.
Youngman attended Harvard, where he was a member of the debate team.
Youngman served with a troop of Pennsylvania Cavalry during the Spanish–American War; he also served in World War I.
In 1932 Youngman was the Republican nominee for Governor of Massachusetts, he lost that election by about 150,000 votes to the incumbent Democratic Governor Joseph B. Ely.