シリーズ15作目。せめて夢の中ではヒーローになりたいと願うのび太は、「気ままに夢見る機」で“夢幻三剣士”という夢の世界へ。
妖精シルクに案内され、ユミルメ国についたのび太は、悪の妖霊大帝オドロームを倒せば、王女シズカリア姫と結婚できることを知り、さっそく白銀の剣とかぶとを手に入れると、剣士ノビタニアンとなって妖霊大帝を倒す冒険の旅に出る！
Tired of constantly having nightmares, Nobita ask for Doraemon to bring a Dream Machine which would allow Nobita to dream of anything he wants. After an attempt to have a dream about the fall of Atlantis fails, he chooses a dream where he is in a fantasy world with an inspiration from The Three Musketeers. Together Nobita and his friends must defeat the evil King before he escapes from Nobita's dream into other people's dreams.
