Olive oil consists mainly of omega-9 fatty acids, above all oleic acid. It also contains smaller amounts of omega-6 (linoleic acid) and only very little omega-3 (linolenic acid), usually under one per cent.
If you are looking for a lot of omega-3, you will find it more in linseed oil, walnuts or oily fish. Olive oil's strength lies elsewhere: in its high share of monounsaturated fatty acids and in its polyphenols. Together they make it the most versatile oil in the kitchen.