The IGS Weytahn was an Andorian Imperial Guard warship in service during the Earth-Romulan War. It was presumably named after the heavily contested world of Weytahn on the border of the Andorian Empire and the Confederacy of Vulcan.
In 2156, the Weytahn was under the command of General Hravishran th'Zoarhi when it engaged in the Battle of Andoria. The Weytahn received severe damage to its propulsion system, meaning the Weytahn could not pursue the Romulan ship when it attacked Andoria. (ENT novel: Beneath the Raptor's Wing)