I removed a ceiling fan and would like to replace it with a simple light fixture. I have a white, black and blue wire coming from the ceiling. The light fixture has only a white, black and ground wire. Can I just cap off the blue wire and leave it in the box? Thanks so much.

You can safely and legally, but is the black controlled by a wall switch?

Don't usually find a blue wire in a household cable as current carrying, typically red. Blue is usually the light wire in the fan. Do you have 2 switches? What color are the switch wires.

When you took down the fan, what was the blue wire connected to? I'll venture a guess that it was the light wire on the fan. Do (did) you have two switches controlling the fan?