Anna is the largest city and retail trade center in Union County, Illinois, United States.

It is known for being tied to its close neighbor Jonesboro, together known as Anna-Jonesboro, and of which the main public high school for the two towns is named.

Anna is known for the Choate Mental Health and Development Center, a state facility that opened in 1869.

[7] The coming of the railroad can be credited for prompting the founding of the City of Anna, although, from the time of the George Rogers Clark expedition into Southern Illinois country, emigrants recognized its agricultural possibilities.

For the purpose of farming, fruit growing, gardening, and dairying, the lands in and around Anna are not surpassed in Southern Illinois.

[5] The precinct in which Anna lies is situated on the divide between the waters of the Ohio and Mississippi Rivers and is well drained by the Cache, Cypress, and Big Creeks.

The business ran until 1900, according to an exhibit at the Union County Historical Society Museum in Cobden.

[8] During the American Civil War, Camp Anna in 1862 was the mustering and training location for some Illinois Infantry regiments, including the 81st,[9][10] 109th,[11][12] and 110th.

[22] Signs using a pejorative for Black people warning them not to let the sun go down on you in Anna persisted on Highway 127 until the 1970s.

The library was designed by Walter Burley Griffin, an understudy to Frank Lloyd Wright, in 1913 and constructed in 1913–14.