William Nichols, Sr. (1780 – December 12, 1853) was an English-born architect who emigrated to the United States and became most famous for his early Neoclassical-style buildings in the American South.

[2][3][4] William Nichols was born in 1780 in Bath, a center for English Palladian and Adam-style architecture in the 18th century.

Incorporating Palladian and early Greek Revival elements, it included a new central rotunda surmounted by a dome.

Another of his jobs was the 1825 remodeling of the Governor's Palace at the end of Fayetteville Street in Raleigh, which included the addition of a monumental Ionic portico.

[5] In 1833, with a letter of recommendation from his friend, Alabama Governor John Gayle, Nichols applied for the post of state architect for Mississippi.

Although he didn't receive the job at the time, he was later summoned to Jackson in 1835 to fill the post and assume construction of the new Mississippi capitol.

The configuration and ornament on the new building reflected his earlier statehouses in North Carolina and Alabama, on a grander scale.

Between 1959 and 1961 it was renovated for use as a state historical museum and served that purpose until 2005 when Hurricane Katrina seriously damaged the building.