Sogen Kato (22 July 1899 – c. November 1978) was a Japanese man thought to have been Tokyo's oldest man until July 2010, when his mummified corpse was found in his bedroom. He likely died in November 1978, aged 79, but his family kept his body hidden in a back room and a government pension for 32 years after death.

His case is an example of a ghost case, where someone is 110+ and "alive" on paper but actually had died earlier (sometimes much earlier).