But unless you're following custom or tradition, it's probably best to wait at least until your baby can support his head when you hold him on your lap, which is around 3 months. This will make his first haircut a lot easier on everyone involved. Some salons have a minimum age requirement, so call ahead to check before bringing your baby. Of course, if your baby has a lot of hair and you feel it needs trimming before you want to take him for a real haircut, you can do the job yourself at home.