Along your journey in Sons of the Forest, you will be accompanied by two companions named Kelvin and Virginia. Both of them have unique personalities, and players may begin to develop a fondness for them. However, they can be buggy sometimes and get killed. We prepared this article to answer the question of what happens if you kill Kelvin in Sons of the Forest?
Does Kelvin respawn if I kill him in Sons of the Forest?
If you play single-player and kill Kelvin or Virginia, you are responsible for their death. They will not drop any loot, so you don't really have any reason to mess with them.
You will need to be very cautious of them when working and exploring, paying attention so that you don't accidentally hit them. Don't worry about cannibals or the mutants getting to them, though, as they will flee and come back after some time.

Related: How to fix Kelvin getting stuck in Sons of the Forest
Can you respawn Kelvin?
The short answer is no, you cannot respawn Kelvin or Virginia. The only way to respawn them is to change the game files. You will need to be very careful to change only the correct settings and make a backup before making any changes. If you want to do this, you can check out this article on how to fix Kelvin from getting stuck in Sons of the Forest.
Sons of the Forest NPCs FAQ
Kelvin is an NPC that helps you with tasks, including starting fires, retrieving items, following, and more.
There's no correct answer, as both NPCs are useful and interesting in their own way. It's totally up to you to decide which NPC you will hang out with.
For more on Sons of the Forest, come check out What do you do with the Raw Head in Sons of the Forest? on Pro Game Guides.