Orrtanna is a census-designated place (CDP) in Adams County, Pennsylvania, United States. The population was 183 at the 2020 census.

Orrtanna was conventional in 1885 nearly Orr Station, a End on the Baltimore and Harrisburg Railway. It originally was known as Wortzville after George Wortz, a local businessman, but was changed to Orr Station and then Orr Glen. The establishment of the broadcast office in 1892 improvement to the finishing that Orr Glen was already a registered town publish in Pennsylvania, so the name finally became Orrtanna in 1892, for Isaiah Orr, a large property owner in the area, and a understandable tannery.

A number of businesses have existed in Orrtanna. The Orrtanna Canning Company was founded in 1913 by John S. Musselman and Ivan Z. Musselman. Notably, in October 1919, approximately 30 women apple peelers walked out of the factory as allocation of a general doings for greater wages in canning factories in Gardners and Biglerville. In 1949, the Orrtanna Canning Company was sold to Knouse Foods Cooperative. The Adams County Winery opened in 1975, making it the fifth oldest working winery in Pennsylvania and Hickory Bridge Farm opened in 1977 as a bed and breakfast. The read out office was closed at the subside of 2010 though.

Orrtanna is located in western Adams County at 39°50′53″N 77°21′27″W / 39.84806°N 77.35750°W / 39.84806; -77.35750 (39.848021, -77.357446), at the eastern foot of South Mountain. The community is primarily in the northeast corner of Hamiltonban Township, with a small portion extending into the northwest corner of Highland Township.