Sega Meganet, also known as the Net Work System, was an online service for the Mega Drive in Japan and later Brazil.

Utilizing dial-up Internet access, Meganet was Sega's first online multiplayer gaming service, and functioned on a pay to play basis.

The system functioned through the use of a peripheral called the Mega Modem and offered several unique titles that could be downloaded, and a few could be played competitively with friends.

Retrospective feedback praises the attempt by Sega to introduce online gaming, but criticizes the service for its logistical issues and lack of titles.

The Mega Modem also came packaged with a cartridge which allowed for access to the Meganet game library, and approximately six titles were available at launch.

Adam Redsell of IGN commented on the basic features of the service, and despite noting that Meganet received only a few games, stated "[T]hat's pretty damn impressive for 1990".

)"[12] The same issues that plagued the Meganet over the use of phone lines for Internet connectivity would later resurface when Catapult Entertainment launched the XBAND service in 1994.

[4] Ken Horowitz of Sega-16 took note of Sega's reluctance to commit to releasing the service in North America as part of the reason for its lack of titles, noting, "Companies were most likely waiting for confirmation of the modem’s release before they began to commit themselves, and as time has attested, few were waiting to go ahead with development in light of Sega's 'wait and see' attitude."

Horowitz went on to criticize this issue as a problem Sega would have again with the 32X in 1994, stating, "History would repeat itself in the harshest of manners only five years later.