Godzilla: Tokyo S.O.S. (ゴジラ×モスラ×メカゴジラ 東京SOS, Gojira Mosura Mekagojira Tōkyō Esu-Ō-Esu) is a 2003 Japanese kaiju film directed by Masaaki Tezuka, with special effects by Eiichi Asada. Distributed by Toho and produced under their subsidiary Toho Pictures, it is the 28th film in the Godzilla franchise, the fifth film in the franchise's Millennium series, the 27th Godzilla film produced by Toho, and a direct sequel to the 2002 film Godzilla Against Mechagodzilla. The film features the fictional monster characters Godzilla and Mothra, along with the mecha character Mechagodzilla, who is referred to in the film by the name Kiryu.

Godzilla: Tokyo S.O.S. stars Noboru Kaneko, Miho Yoshioka, Mitsuki Koga, Masami Nagasawa, Chihiro Otsuka, Kou Takasugi, Hiroshi Koizumi, and Akira Nakao, with Tsutomu Kitagawa as Godzilla and Motokuni Nakagawa as Kiryu. It is the only installment in the franchise's Millennium period to share continuity with a previous Godzilla film besides the original 1954 film and also shares connections with Mothra (1961).

The following entry in the series, Godzilla: Final Wars, was released on December 4, 2004.