| William Elting Johnson | |
| Office: | Member of the New York State Senate from the 38th district |
| Term Start: | January 1, 1896 |
| Term End: | December 31, 1900 |
| Predecessor: | New district |
| Successor: | George E. Green |
| Party: | Republican |
| Birth Place: | Westtown, New York, U.S. |
| Birth Date: | October 17, 1837 |
| Death Place: | Waverly, Tioga County, New York, U.S. |
| Parents: | Alexander T. Johnson Jane (Cuddeback) Johnson |
| Spouse: | Mattie Maria Fuller (m. 1873) |
| Children: | 1 |
| Alma Mater: | Albany Medical College |
William Elting Johnson (October 17, 1837 in West Town, Orange County, New York – December 16, 1912 in Waverly, Tioga County, New York) was an American physician and politician from New York.
Johnson was the son of Alexander T. Johnson (1811–1898) and Jane (Cuddeback) Johnson (1811–1904). He attended the common schools. He graduated from Albany Medical College in 1859, and practiced medicine in Waverly. During the American Civil War he was an army surgeon from 1862 to 1865 with the 109th New York Volunteers. Afterwards, he resumed the practice of medicine in Waverly. On May 1, 1873, he married Mattie Maria Fuller (1847–1914), and they had one daughter.
Johnson was a presidential elector in 1888, voting for Benjamin Harrison and Levi P. Morton; and a member of the New York State Senate (38th D.) from 1896 to 1900, sitting in the 119th, 120th, 121st, 122nd and 123rd New York State Legislatures.
He died on December 16, 1912, at his home in Waverly, of pneumonia.