The pylon sign installed at the resort in 1976 and two feather plumes stand about 20 feet tall and 30 feet wide were displayed at the property for nearly three decades.
"The Flamingo serves as a huge part of Las Vegas history, and we are honored to help preserve some of their story," Neon Museum executive director Aaron Berger said.
The Flamingo, which opened in 1946, was the third resort on Las Vegas Boulevard.
The restoration was made possible by donors Emily Conner Cooper, wife of the late comedian Pat Cooper; Andrew Pascal, CEO of PlayStudios, a developer of mobile and social gambling products; and Felicia French, CEO of Opuzen, a fabric supplier for the interior design industry.
The Neon Museum is open daily and includes an outdoor exhibition space known as the Neon Boneyard; the North Gallery, home to the audiovisual experience "Brilliant! Jackpot," which re-illuminates more than 40 nonoperational signs; the Boulevard Gallery outdoor exhibit and event space; and a visitors center in the former La Concha Motel lobby.