Mamia I Gurieli (Georgian: მამია I გურიელი; died 1534), of the House of Gurieli, was Prince of Guria from 1512 until his death in 1534. Succeeding on the death of his father Giorgi I Gurieli, Mamia became involved in the conflict between the two eastern Georgian kingdoms of Kartli and Kakheti in 1520; by force of arms, he compelled David X of Kartli to agree on peace with Levan of Kakheti, his son-in-law. Mamia Gurieli's 1533 campaign, jointly with his namesake Prince of Mingrelia, against the homebase of Circassian pirates ended in a fiasco, with Mamia being captured and ransomed later that year.
Mamia was a son of Giorgi I Gurieli, on whose death he succeeded as mtavari ("prince") of Guria, a polity in western Georgia, on the Black Sea coast, which emerged as a sovereign principality after the dissolution of the Kingdom of Georgia in 1491. Mamia acceded to the throne by blessing of King Bagrat III of Imereti, his royal suzerain. In modern historiography, he is sometimes assigned the regnal number "III" by virtue of his being the third Mamia with the style of Gurieli, the first being a son of Kakhaber I Gurieli and the second being Mamia (II) Gurieli.
In 1520, Mamia was approached by Levan, king of Kakheti in eastern Georgia, with the request that he marry his daughter to Levan and aid the king against the encroachments of King David X of Kartli. Mamia, having secured for his troops a free passage from the atabeg of Samtskhe, traversed Ghado mountain, advanced into Kartli and defeated David X at Mokhisi. The latter fell back to his capital of Tbilisi and was setting a counter-attack in motion, when a dignitary, sent by Gurieli for parley, persuaded the king to join Mamia and Levan of Kakheti at a peace summit at Mukhrani. After the peace arrangement, Mamia sent his daughter Tinatin to marry Levan.