Thornhill, historic plantation in Talladega County, Alabama, United States

Thornhill, also known as the Hade–Lewis House, is a plantation in Talladega County, Alabama. Its main house is a two-story Classical Revival I-house, five bays wide with a central portico, a central hall plan, and a rear ell containing a parlor, dining room, library, and kitchen. The property also includes a chapel, servants' quarters, plantation office, barn, horse racetrack, family cemetery, and approach road.

John Hardie, a Scot who arrived in Alabama in 1818, purchased the land in 1834 and built the house starting in 1835. The estate was primarily used for cotton cultivation and relied on about 50 enslaved workers whose labor sustained both the household and plantation operations.

John Hardie named the property after his father's Thorn Hill Farm in Kinross, Scotland, because the land's topology reminded him of it. The house follows a central hall plan, with a parlor, dining room and library opening off the hall and a kitchen in the rear ell.

Thornhill lies within the city limits of Talladega, and the property is reached by an approach road off the main route. The grounds hold the main house, a chapel, servants' quarters, a plantation office, a barn, a horse racetrack and the family cemetery, so allow time to walk between them. The site was listed on the National Register on February 20, 1998.

The estate bears a personal connection to Hardie's Scottish heritage, as he named it after his family's Thornhill farm in Scotland, reflecting a direct link to his homeland. The racetrack on the grounds reveals that the plantation was not solely focused on agriculture but also served as a venue for leisure activities and the social life of the wealthy family.