In episode 151 where Bellamy uses Spring Hopper at Jaya and launches around the buildings, Luffy punches him. But does he kill him or just knock him out ?
No, Belammy is alive.
In the pre-Skyisland arc when Luffy goes to retrieve the gold from him, he just knocks him down and doesn't kill him.
In the CP9 saga, it is shown that Doflamingo was forcing Bellamy to fight.
Next is the Pirate Alliance Arc.
Bellamy entered the Corrida Colosseum to compete for a leadership position in the Donquixote Family and was assigned to Block B. He is first seen somewhere in the Colosseum crushing someone's skull.
Belammy vs Abdullah and Jeet.
These are just two of a few events that prove that Bellamy wasn't killed by Luffy. There has been some more events with appearance of Bellamy.
Luffy hasnt really killed anyone in the whole series except for a few Sea Kings :P