Hamilton and Rhoda Littlefield House

Washington Square Historic District is a national historic district located at Oswego in Oswego County, New York. It includes 39 contributing buildings, one contributing structure, and one contributing site. It encompasses the historic civic and religious center on the east side of the city. There are 37 residences, four churches, a synagogue, a public green, the county office building, and County Courthouse, and a former railroad tunnel. Located within the district are the separately listed Hamilton and Rhoda Littlefield House, Richardson-Bates House, Oswego City Library, and Oswego County Courthouse. Washington Park was laid out in 1797 when the city of Oswego was laid out.It was listed on the National Register of Historic Places in 2009.

Richardson-Bates House is a historic home located at Oswego in Oswego County, New York. It is constructed primarily of brick and built in two stages. The main section is a 2+1⁄2-story, Tuscan Villa style brick residence with a gable roof and 4-story tower designed by architect Andrew Jackson Warner about 1867. The interior features carved woodwork by Louis Lavonier. The South wing addition included a private library, formal dining room and kitchen that was completed in 1889.The house and its contents were donated to the Oswego Historical Society in 1947. It was listed on the National Register of Historic Places in 1975.

Oswego County Courthouse is a historic courthouse located at Oswego in Oswego County, New York. It was built in 1859-1860 and altered in 1891 and again in 1962. The two story building rises above a cruciform plan and is constructed of load bearing masonry walls faced with smooth ashlar limestone. It features a portico surmounted by a domed cupola. It was designed by architect Horatio Nelson White (1814–1892).It was listed on the National Register of Historic Places in 2000.

John B. and Lydia Edwards House is a historic home located at Oswego in Oswego County, New York. It is a two-story, rectangular frame residence built between 1834 and 1835. Its owner John B. Edwards was abolitionist Gerrit Smith's agent at Oswego and the house is well documented as a way station on the Underground Railroad.It was listed on the National Register of Historic Places in 2001.

Oswego City Library is a historic library building located at Oswego in Oswego County, New York. It has also been known as the Oswego School District Public Library. It was built in about 1855 and is a two-story brick structure over a full basement. It features a distinctive castellated style with exterior battlements, machicolations, tower, turrets, corbels, and arcaded windows. It was a gift from Gerrit Smith, who gave $25,000 for the building construction and $5,000 for books.The library is credited for being the oldest public library in the United States that maintains operations out of its original building.It was listed on the National Register of Historic Places in 1971.

Oswego () is a city in Oswego County, New York, United States. The population was 16,921 at the 2020 census. Oswego is located on Lake Ontario in Upstate New York, about 35 miles (56 km) northwest of Syracuse. It promotes itself as "The Port City of Central New York." It is the county seat of Oswego County. The city of Oswego is bordered by the towns of Oswego, Minetto, and Scriba to the west, south, and east, respectively, and by Lake Ontario to the north. Oswego Speedway is a nationally known automobile racing facility. The State University of New York at Oswego is located just outside the city on Lake Ontario.

Edwin W. and Charlotte Clarke House is a historic home located at Oswego in Oswego County, New York. It is a 2+1⁄2-story brick Italianate style residence built in 1857. Edwin W. and Charlotte Clarke were prominent abolitionists and it is believed that the house was a way station on the Underground Railroad.It was listed on the National Register of Historic Places in 2002.

The Safe Haven Museum and Education Center is a museum in Oswego, New York that tells the story of 982 mainly Jewish refugees who fled Europe in the U.S. Government "Safe Haven" program. They came to the Fort Ontario Emergency Refugee Shelter in Oswego, New York, in August 1944. Safe Haven was the only official U.S. Government activity to rescue Jewish refugees during the Second World War, for victims of the Nazi Holocaust. The refugees were brought from Italy, but deliberately only from other parts of Europe. They were all fleeing from the Nazis. They were deliberately chosen so that some incoming refugees were non-Jewish, so as to allay anti-semitic fears. They were placed in Fort Ontario, behind barbed wire, and given no official status, and were told they would be returned to their homelands after the war, and would have no rights as regards entering the United States. In fact, due to political pressure, at the war's end they were allowed to stay in the United States. Parenthetically, the group included a whole group of Boy Scouts.

The Fort Ontario Emergency Refugee Shelter, also known as "Safe Haven", located in Oswego, New York was the first and only refugee center established in the United States during World War II. From 1944 to 1945, the shelter housed almost 1000 European refugees, predominantly of Jewish descent. The effort was called "Safe Haven". The refugee shelter is now the Safe Haven Museum and Education Center.

Oswego Armory is a historic National Guard armory located at Oswego in Oswego County, New York. It is a brick and stone castle-like structure built in 1906–1908. It was designed by State architect George L. Heins. It consists of a 2+1⁄2-story administration building with an attached large, gable-roofed drill shed. The building features a 5-story octagonal tower at the northwest corner.It was listed on the National Register of Historic Places in 1988.

Standard Yarn Company Building is a historic factory building located at Oswego in Oswego County, New York. It is a brick structure, measuring 200 feet along the street and constructed in three sections between 1897 and 1911. It is of common mill construction with load bearing masonry walls and wooden floors and joists supported by heavy wooden posts.It was listed on the National Register of Historic Places in 2008.

Market House, also known as The Market Hall and The D.L.& W. Hall, is a historic market building located at Oswego in Oswego County, New York. It was built in 1835 and is a massive brick and stone structure overlooking the Oswego River. The structure originally housed several government entities including city hall. A new city hall was constructed in 1870 and completed in 1872. A section of the basement is believed to have been used as a jail. In 1864 the city sold it to the Oswego and Syracuse Railroad, that used it for the next 80 years as office and storage space. The railroad upgraded the building with a bracketed cornice and elaborate cupola.It was listed on the National Register of Historic Places in 1974. The structure is privately owned, and a bar located on the north-most section of the first floor, named "Old City Hall" has been there for many years.