The flag of Sioux Falls, South Dakota, consists of a zigzag pattern of thin white and blue lines, which divides an upper blue portion and a lower pinkish-red portion, and a yellow sun in the upper left corner.

It was chosen as the winner of a design competition for both the "Best in Show" by a panel of experts and the "People's Choice" award.

The invited speaker Roman Mars noted that Sioux Falls was one of only three major U.S. cities (along with Fargo, North Dakota, and Hilo, Hawaii) not to have an official flag.

[2][13] OTA combined with the Sioux Falls Design Center and the American Institute of Graphic Arts to form The Committee to Establish a Suitable Flying Banner for the City of Sioux Falls (CESFBCSF) to design a flag for the city.

[13] One flag won both the "Best in Show" by a panel of experts and the "People's Choice" award from over 3000 community votes.

[2][3] There was a renewed push to get the flag approved in 2018 after the election of a new mayor, Paul Ten Haken.

The flag has appeared on t-shirts of local businesses, on the jersey of the Sioux Falls Skyforce professional basketball team, and even on a Metallica concert graphic.