I had a tooth removed now an abscess has appeared above where it used to be. will amoxicillin get rid of this?

Depends: If the infected tooth has already been removed and there is an infection still present, you need to go back to the dentist for a follow up. He or she will prescribe antibiotics if appropriate. There may be better treatments that don't require antibiotics, and you may find that there is another infected tooth nearby that needs attention to get rid of the abscess.

Possibly: An abscess is a fluid collection that typically requires drainage to resolve it completely. Amoxicillin may help to localize the infection and treat the associated cellulitis. I'd also be concerned that perhaps a fragment of tooth or loose bone may still be present that requires removal.