Krasnooktyabrsky () is an urban locality (an urban-type settlement) in Medvedevsky District of the Mari El Republic, Russia. As of the 2010 Census its population was 4,559.
It is located 9 km northwest of Medvedevo, Nolka railway station.
An arsenal of the Russian Armed Forces is located in the town.
Within the framework of administrative divisions, the urban-type settlement of Krasnooktyabrsky is incorporated within Medvedevsky District as Krasnooktyabrsky Urban-Type Settlement (an administrative division of the district). As a municipal division, Krasnooktyabrsky Urban-Type Settlement is incorporated within Medvedevsky Municipal District as Krasnooktyabrsky Urban Settlement.