The pavilions are named for Exelon, a Chicago-based company that generates the electricity transmitted by its subsidiary Commonwealth Edison (ComEd). The city of Chicago has collaborated with Exelon and ComEd on a variety of environmental projects, including the installation of solar power in buildings, support for sustainable design and renewable energy, and furthering educational and social awareness of green architecture in the city. The pavilions cost $7 million, $5.5 million of which was donated by Exelon and ComEd.
The lead designer for the North Pavilions was Thomas H. Beeby of Hammond Beeby Rupert Ainge Architects. Beeby's designs for the North Pavilions are "in harmony with the Harris Theater", for which he was the architect as well. The North Pavilions are along Randolph Street on either side of the theater, which is Millennium Park's indoor performing-arts venue.
The South Pavilions were designed by architect Renzo Piano of Renzo Piano Building Workshop. Piano designed the Art Institute of Chicago's Modern Wing, which is across Monroe Street from the South Pavilions and opened in 2009. The facades of the South Pavilions are limestone and glass in order to complement the Modern Wing, even though it was not completed until several years after the pavilions were finished. Piano also designed the Nichols Bridgeway, which connects Millennium Park and the Art Institute, and is next to the Southwest Pavilion.