• Year First Flown:
• Designed By:
• Design: A light blue flag with the state seal placed in the center and surrounded by yellow rays simulating the sun. The seal includes images of: a farmer, a metal factory, trees, a steamship, and the motto "Under God the People Rule". Encircling the seal are the words "South Dakota the Mount Rushmore State" written in yellow.
• Meaning: The symbols included in the state seal and flag were chosen to represent the diverse industries and resources of the state of South Dakota. The farm and the farmer are meant to represent the state's agriculture, while the metal smelter symbolizes the state's manufacturing and mining industries. The trees pictured stand for the state's timber industry and the steamship is a sign of commerce. The date "1889" signifies the year that South Dakota joined the Union, while the motto "Under God the People Rule" is the official state motto of South Dakota. The sun rays encircling the seal are a tribute to the state's earlier nickname "The Sunshine State".

South Dakota became the 40th state to join the Union on November 2nd, 1889. When South Dakota was made a state, a man named Seth Bullock was appointed to the position of U.S. Marshall. Bullock had a long history with South Dakota and had dedicated his life to the betterment of the territory/state. In 1871 Bullock began his career as the territorial senator of South Dakota, then became the sheriff of the infamous Deadwood, South Dakota. After South Dakota became a state, Bullock asked the state's senator, Ernest May, about the possibility of an official state flag. Senator May then turned to Doane Robinson, the Secretary of the State Historical Society, to handle the creation of a state flag. Robinson tasked Ida Anding McNeil with the design of the flag. In 1909, Ida presented a flag design with a sun on one side and the state seal on the other. Senator May liked the designed, and approved it with Senate Bill 208. In 1963, State Representative William Sahr suggested that the flag be modified in order to make the flag's production more cost efficient. Production of the South Dakota state flag was too expensive and intricate because it had a different design on either side of the flag. Sahr suggested that if the design was the same on either side it would be cheaper to produce and more people would be able to afford to buy it. The State Legislature agreed with Sahr and approved the new flag design on March 11th, 1963.

The flag's design was changed one more time in 1992, when the state nickname of South Dakota changed to "The Mount Rushmore State". South Dakota was once promoted as "The Sunshine State" because of the large amount of sunny days that the state had every year. However, when Florida began to use the phrase "The Sunshine State" South Dakota changed their nickname in order to remain unique.