Gedko Sasinowic (Gedko, son of Sasin) (died 1223) was a medieval Bishop of Płock.
Born into the Ogończyk nobile family. He was son of Sasin and nephew of Żyro.[1] Gedko, bishop of Kraków, was his father's cousin.[1]
He was made provost of the chapter of the Cathedral of Kraków in 1189 and in 1206 became bishop of Płock.[2]
He is first attested in correspondence with Christian of Oliva the bishop of Chełmno, in Prussia, in a document dated 5 August 1222. Here he appears to be subordinate to the Prussian Bishopric. Płock appears to have been a base for missionary activity into Prussia at this time.[3]
He is also recorded as approving the donation of the Pope Honorius III in the Bull Cum a nobis petitur in 1223.
The death of Gedko in 1223 left a power vacuum and the bishops throne remained vacant for two years as it was disputed between Jan Gozdawita and Gunter Prus. Both men eventually became Bishop.