The simple answer is yes, but it varies how it is possible.
In the one-shot comic "Hulk: The End" written by <PERSON>, <PERSON> is almost invincible. He survives a nuclear holocaust when no one else does. Although, <PERSON> is not invincible. He dies and hulk realizes he cannot transform without dying also. From the synopsis:
Suffering a painful heart attack, <PERSON> realizes how much his punishment resembles that of <PERSON>, the Last Titan; condemned to stay forever alive even while animals devour him, speculating that the <PERSON>'s suffering is Earth punishing him for humanity's sins as the embodiment of the nuclear wars that destroyed Earth. As he dies, the <PERSON>'s persona arises in his mind. [...]
The next morning, the <PERSON> somberly sits outside the cave, musing in his inner monologue: "<PERSON> is gone...got rid of him last night." As he remembers the confrontation, he realizes that if he were ever to change back to <PERSON>, he would die also.
In the <PERSON> version of <PERSON>, there was a TV movie called The Death of the Incredible Hulk. <PERSON> falls from a exploding plane and dies on the ground. 516
Although in true comic style, "there was talk of another Incredible Hulk television movie which would resurrect the character." Unfortunately, <PERSON> (who portrayed <PERSON>) dies before that ever happened.
In the comics Tales to Astonish #90 & 91, the Abomination is created and kills <PERSON>. He is revived shortly after though.
In the Old Man Logan comic series, <PERSON> kills and eats <PERSON>. "<PERSON> recuperates within <PERSON>'s stomach and bursts out, killing him." See below:
In Thor #73 (The Reigning Part 5), <PERSON> kills the <PERSON> and others. Although, I believe at the end of The Reigning story arc <PERSON> turns back time. This gallery has several pages from that issue, such as the one below. <PERSON> also snapped <PERSON>'s neck in a What If? issue that I couldn't find.
Other characters have supposedly killed the <PERSON>, such as <PERSON>, <PERSON> (<PERSON>) and <PERSON>. But they were all in "what if?" type comics, and I couldn't find solid details online. I found evidence that <PERSON> killed Red Hulk (not the opposite), but this stands to reason if one hulk can die, the <PERSON> could die.
More recently, <PERSON> was killed by <PERSON> in What If...? Season 1, Episode 3 by entering his body with his Ant-Man suit and increasing <PERSON>'s cells using pym particles until he exploded. 663