House Hightower of the Hightower is one of the most powerful of the noble houses in the Reach. Their seat is the Hightower, located in the city of Oldtown. The sigil of House Hightower is a stone white watchtower, with a fire burning on the top. Their motto is "We Light the Way". They possess a Valyrian steel sword called Vigilance.

The Hightowers are among the oldest and proudest of the Great Houses.  The Hightowers can be legitimately referred to as being either "of Hightower" or "of Oldtown."

While historically they have often preferred trade instead of war, and have also avoided many wars because of their support for the Faith of the Seven, they were the primary supporters of the First Targaryen Rebellion, due in no small part to the late Lord Lymond Hightower's marriage to Rhaelle Targaryen.