Robert Hall Baker Sr. (June 27, 1839 – October 5, 1882) was an American businessman and Republican politician from Racine, Wisconsin.

[1][2] Born in Geneva, Walworth County, Wisconsin Territory, to Martha Washington Larrabee and Charles Minton Baker.

Baker attended Beloit College and assisted his father's law practice in Lake Geneva before moving to Racine.

[1] In 1856, he entered business in Racine hardware supply, then worked for one year with Thomas Falvey, a reaper manufacturer.

In 1874 he was elected to return to the Senate, defeating incumbent Liberal Republican Charles Herrick.