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)

In 1853, he was President of the Confederation, presiding the council.