Adolf Deucher (15 February 1831, in Wipkingen – 10 July 1912, in Bern) was a federal councillor of Switzerland, and a two-time member of the Swiss National Council. Pursuing centralist policies in a very federalist country, he was a main promoter of the 1868 revision of the Swiss constitution.
As a federal councillor, he improved conditions for workers (banning phosphorus in the match industry in 1898, revision of the factory law). He was also the guiding force behind the first national law on agriculture.
He studied medicine at Heidelberg, Zurich, Prague, and Vienna. In 1855 he became a member of the council of his canton (Thurgau), and in 1868 he served as a member of the council established to formulate a new democratic constitution for Thurgau. From 1869 to 1873 he was a member of the National Council of Switzerland, and, three years after his re-election to that body became its president (1882).
He was elected to the Swiss Federal Council on 10 April 1883 and died in office on 10 July 1912, aged 81. He was affiliated with the Free Democratic Party. During his office time, he held the following departments:
- Department of Justice and Police (1883)
- Department of Posts and Railways (1884)
- Department of Home Affairs (1885)
- Political Department (1886)
- Department of Trade and Agriculture (1887)
- Department of Industry and Agriculture (1888–1895)
- Department of Trade, Industry and Agriculture (1896)
- Political Department (1897)
- Department of Trade, Industry and Agriculture (1898–1902)
- Political Department (1903)
- Department of Trade, Industry and Agriculture (1904–1908)
- Political Department (1909)
- Department of Trade, Industry and Agriculture (1910–1912)
He was President of the Confederation four times in 1886, 1897, 1903 and 1909.