S. Holton Farm

Rosedale is a historic home located near Middletown, New Castle County, Delaware. It was built about 1801, and consists of a two-story, brick rectangular main block with a two-story rear ell. Also attached is a three-bay, one-story wing constructed of a wood siding and two wings added to the rear (south) between 1960 and 1965. It has a center hall plan. It has a slate-covered gable roof, interior end chimneys, and a front entrance with fanlight. Also on the property are a contributing hay barn, barn, and mash furnace.It was listed on the National Register of Historic Places in 1985.

Armstrong-Walker House is a historic home located near Middletown, New Castle County, Delaware. It was built about 1870, and consists of a 2+1⁄2-story, five bay brick main block with a service ell and later frame kitchen addition. The house features an open front porch with square, paneled posts. Also on the property is a contributing braced frame stable.It was listed on the National Register of Historic Places in 1985.

Maples is a historic building located near Middletown, New Castle County, Delaware. It was built about 1855, and is a two-story, L-shaped, frame dwelling. It is in the Delaware vernacular style with Greek Revival and Second Empire style details. The building has a wraparound porch with flat roof, a cross-gable roof, and interior end chimneys.It was listed on the National Register of Historic Places in 1978.

Fields Heirs, also known as Fields House, was a historic home located at Middletown, New Castle County, Delaware. It was built about 1820, and was a 2+1⁄2-story, five-bay by two-bay center-hall plan residence with a 1+1⁄2-story rear wing forming an L-shaped house. It sat on a stone foundation and had a gable roof. Also on the property was a contributing drive-through granary.It was listed on the National Register of Historic Places in 1985 and demolished between 1992 and 2002.

Appoquinimink High School (AHS) is a public high school in Middletown, Delaware. It is a part of the Appoquinimink School District.Construction of the two-story building began in 2006 and ninth grade students were housed in the former Alfred G. Waters School building for the duration of the construction. Felecia Duggins was selected as school principal in May 2007 and the campus' stadium and 1,067-seat fieldhouse opened that fall. Administrators gave students at Everett Meredith and Louis L. Redding middle schools the choice between the jaguars, pirates, and titans for the new high school's mascot; the most popular choice was the jaguar.The school opened in 2008 and has a capacity of 1,600 students.

Greenlawn, also known as the Outten Davis House and William Brady House, was a historic home located at Middletown, New Castle County, Delaware. It was built about 1810, and radically altered about 1860. It was a two-story, five-bay, brick dwelling with cross-gable roof with dormers. It had a rear brick ell with attached wing. It featured a three-bay front porch, large brackets, a widow's walk on the roof, and ornate chimney caps. It was originally built in the Late Georgian style, then modified with Late Victorian details.It was listed on the National Register of Historic Places in 1973 and demolished in about 1985.

Choptank, also known as the J. Clayton Farm, is a historic home located near Middletown, New Castle County, Delaware. It was built about 1850, and is a three-story, five-by-two bay, timber-frame structure on a brick foundation. It has a low-hipped roof. Also on the property are a contributing large barn, corn crib, and shed.It was listed on the National Register of Historic Places in 1985.

Choptank-Upon-The-Hill is a historic home located near Middletown, New Castle County, Delaware. It was built about 1820, and is a 2+1⁄2-story, five-bay, brick house with a 2+1⁄2-story brick ell. The addition was built about 1840–50. The house features a Palladian window above the front facade, a gable roof with dormers, and interior gable end chimney piles.It was listed on the National Register of Historic Places in 1985.

The Middletown Academy was a historic school located in Middletown, Delaware. Founded in 1826 through lottery subscription and constructed the following year, it became part of the public school system in 1876 and was closed in 1929. The school building survives and was listed on the National Register of Historic Places on December 5, 1972. It presently houses the town historical society and chamber of commerce.

Achmester was a historic home and national historic district located near Middletown, New Castle County, Delaware. It encompassed four contributing buildings and two contributing structures. Achmester was built in 1829, and was a 1+1⁄2-story, single pile "Peach Mansion." It consisted of a five bay frame main block with a five bay gable end addition, and five bay rear service ell. It had a gable roof with dormers and sat on a stone foundation. The façade featured simple box cornices and dormers decorated at a later date with Gothic Revival sawnwork trim, pendents, and vergeboards. The contributing outbuildings consist of a cow barn, shed, milk house, granary, and smokehouse. It was built by Richard Mansfield, a founder of Middletown Academy.It was listed on the National Register of Historic Places in 1979. It was demolished in 2022.

The Cochran Grange, also known as John P. Cochran House, is a historic home located in Middletown, Delaware, United States. It was built between 1842 and 1845, and consists of a two-story, five-bay, main block with a two-story wing. The design is influenced by the Greek Revival, Italianate, and Georgian styles. The house features a two-story porch supported by Doric order columns and a flat roof surmounted by a square cupola. Cochran Grange was the home of John P. Cochran, 43rd Governor of Delaware (1875–1879).It was listed on the National Register of Historic Places in 1973.

Middletown Historic District is a national historic district located at Middletown, New Castle County, Delaware. It encompasses 187 contributing buildings in the central business district and surrounding residential areas of Middletown. It is centered on the Middletown crossroads established in the 17th century. Residential buildings include notable examples of the Late Victorian and Federal styles. Notable non-residential buildings include the Witherspoon Inn (1761), S. M. Reynolds and Company (1871), Delaware Trust Company (1918), People's National Bank (1884), and Forest Presbyterian Church (1851). Also located in the district is the separately listed Middletown Academy or Town Hall (1827).It was listed on the National Register of Historic Places in 1978.