Can you get an ultra ball in Pokemon FireRed before killing Snorlax?

No, you cannot get an Ultra Ball in Pokemon FireRed before defeating Snorlax.

Here's why:

* Ultra Balls are found in the game's Victory Road. Victory Road is accessible only after defeating the Elite Four and becoming the Pokemon League Champion.

* Snorlax is encountered on Route 12, long before you can access Victory Road.

Therefore, you cannot obtain an Ultra Ball before encountering Snorlax.