It is Corofin’s first time to reach four consecutive finals and the first since Tuam Stars reached and won their seventh title in-a-row in 1960 that a club has made four deciders in succession.
Milltown, despite a good start, fell away in the second half. Corofin, who will now bid for their 14th crown and 11th since 1991, edged 0-5 to 0-4 in front just before the interval thanks to Justin Burke and he doubled the lead 18 seconds after the restart.
But the crucial score came after 37 minutes when Justin Burke made no mistake from close range. Damien Burke quickly added a point to make it 1-8 to 0-4 and while Michael Martin and Mark Hehir pulled back points for Milltown, Corofin were never threatened.
Meanwhile, in the remaining quarter-final, Mountbellew/Mountbellew drew with Tuam Stars, 0-10 to 2-4. Shane Gaffney notched two goals for the Tuam side in the opening half of a game where they managed just a solitary point after the restart.
In the Galway SHC, Loughrea advanced to the quarter-finals with a hard-earned 1-13 to 0-14 over Tommie Larkins, while two goals from Gerry Murray saw St Thomas advance to the last eight with a 2-9 to 0-11 win over Tynagh-Abbey-Duniry.
Mullagh also advance to the quarter-finals with a 1-19 to 2-8 win over Liam Mellows, while Craughwell sent former All-Ireland champions and neighbours Sarsfields crashing out when they came with a late rally to win by 1-16 to 0-16 and book their place in the last eight.