The Tawi'Yan is the title of an individual in a traditional Klingon wedding ceremony. The name means "sword bearer" in the Klingon language and was their equivalent of a Human "best man". Its origin comes from the wedding ceremony of Kahless the Unforgettable to the Lady Lukara.

In 2374, Alexander Rozhenko was Worf's Tawi'Yan prior to Worf's marriage to Jadzia Dax. (DS9 episode: "You Are Cordially Invited...")