Hello, has it been affected by the frost, are there signs of new growth/buds, try a few bark/stem scrapings for healthy wood, if so be a little patient, are you over watering it?, however i have seen a few olive trees in pots that have been totally killed off to the bad winter weather.julien.

I've a similar problem, mine has lost all bar 4 leaves, which all look pretty dead. Some of the stems towards the base of the tree have healthy wood underneath, but the top half doesn't... Should I give it a good prune to the healthy wood?