Wilhelm Matthias Näff (February 19, 1802 - January 21, 1881) was a Swiss politician.
One of the first seven members of the Swiss Federal Council, he was elected on November 16, 1848, as a representative of St. Gallen. He was affiliated with the Free Democratic Party of Switzerland. During his long tenure, he headed the following departments:
- Department of Posts and Construction (1848 - 1852)
- Political Department (1853)
- Department of Trade and Customs (1854)
- Department of Posts and Construction (1855 - 1859)
- Department of Posts (1860 - 1866)
- Department of Trade and Customs (1867 - 1872)
- Department of Finance (1873)
- Department of Railway and Trade (1873)
- Department of Finance (1874 - 1875)
Successor: Fridolin Anderwert