Hamilton County Courthouse Square is a historic courthouse and jail located at Noblesville, Hamilton County, Indiana. The jail was built in 1875–1876, and is a Second Empire style brick and limestone building. It consists of the two-story, ell-shaped jailer's residence, with a cellblock attached at the rear. It features a three-story square tower that once had a mansard roof. The courthouse was built between 1877 and 1879, and is a three-story, Second Empire style, rectangular brick building. It has a clock tower atop the mansard roof and limestone Corinthian order pilasters.