Héctor's Guitar (previously known as Ernesto's Guitar) is a guitar owned by Héctor from the Pixar film, Coco. It was used by Miguel who was transported to the Land of the Dead. The top of the guitar looks similar to a skull, with a gold tooth like its original owner.
This guitar was a gift given to Héctor by Imelda and went on to become Héctor's instrument during his tour across Mexico. However, his former partner Ernesto de la Cruz stole it along with Héctor's songbook after poisoning and killing him. This guitar would be continuously used until Ernesto's death during his performance of Remember Me in 1942. Ernesto had placed the guitar aside mere moments before he was crushed by a heavy bell, so it survived intact. The guitar was then stored in Ernesto's mausoleum in Santa Cecilia's cemetery.
Much later in the present day, an angry Miguel Rivera breaks into Ernesto's mausoleum on the night of Dia de los Muertos and strums his guitar which causes him to be transported to the Land of the Dead. Much later after Mama Imelda gives him the blessing, he is transported back to the Land of the Living but tries to take the guitar which broke the condition of the blessing (never to play music again) thus transporting him back to the Land of the Dead.
Much later in the film's ending, Miguel runs back home with Héctor's guitar the next morning after being transported back to the Land of the Living after being given a blessing by both Imelda and an almost forgotten Héctor. He uses it to play Remember Me which rejuvenates Mamá Coco's memories of Héctor, thus saving her father from his 'final death'. Since then, the guitar would be used by Miguel as its rightful owner.
Héctor's Guitar appears in Cars 3 as a decoration in Thomasville's Cotton Pin Bar & Grill.
Miguel had made a replica of the guitar, in which he plays while watching one of the Ernesto's films before it was destroyed by his grandmother.