Sarhoyuk, located to the north of the modern Eskisehir city centre, is one of the important mounds in the region having being excavated for a long time. Amongst the unearthed archaeological strata, Late Bronze Age (SH V) layer is one of the best represented cultural phases on the mound. The new hieroglyphic seal, being introduced in this paper, was detected in relation with the very last phase of the Late Bronze Age strata, during the cleansing of the debris of the Hittite Imperial Period layers. With the previously unearthed bulla and a seal, the new seal presented in this paper is the third inscriptive data provided by the Hittite Imperial Period of Sarhoyuk. The button type seal what was made of black stone from bears hieroglyphic script on both sides (side A and B), whose compositions are almost identical except minor details. Due to the seal's fragmentary state, only first two signs are legible on side A and last two signs on side B. The name on side A is read as Luwa with the title "waiter" it is associated with the name Luwa we know from Bogazkoy seals. The male name on Side B, on the other hand, is read as x-wa/i(m)u(wa). The biconvex button seal of Sarhoyuk has a wide area for hieroglyphs which is bordered by a frame, places it in the 13th century BC based on the similar examples.