Where is it - in or outdoors? They should be evergreen but if indoors leaf loss could be due to over/underwatering, lack of light,dry air or temperature shock.

Olives are not really happy as house plants.

its inside where it is usually around 70-80 degrees and 60-70% humidity. Maybe its the watering. How much water should it get? It hasn't grown much since I bought it a year ago.

i have several olive trees that i grew from cuttings from the oldest one which i bought from forest farm about ten years ago. they are all in pots of course zone 5 and every fall when i bring them in befor the frost theydrop over half of their leavesbut they hang on till spring and leaf out again. never had a flower or fruit. i water when they seem dry and give them as much sun as i can indoors. i have several rooted cuttings to trade