Doraemon: Nobita and the Legend of the Sun King (ドラえもん のび太の太陽王伝説, Doraemon Nobita no Taiyōō Densetsu), also known as Doraemon and the Empire of the Sun, is a 2000 Japanese animated science fantasy adventure film, which premiered on March 7, 2000, in Japan, based on the 20th volume of the same name of the Doraemon's Long Tales series. The plot is based on the story The Prince and the Pauper by Mark Twain, where the two main characters switch places.

It premiered on a triple billing with the short films Doki Doki Wildcat Engine and Doraemon: A Grandmother's Recollections. It was a successful film at the box office, grossing around ¥3.42 billion ($32 million), becoming the highest grossing Doraemon film of the original series. It's the 21st Doraemon film. The film celebrates 30 years of the Doraemon franchise.