As temperamental a material as leather is, the last thing anyone wants to see on it is an olive oil stain. Leather is quirky and requires special care so as not to damage it. It is sensitive to water, so simply trying to wash it away isn't an option. For large stains, you should contact a leather professional, but the smaller ones are easy to handle at home. Removing an olive oil stain is an easier process than you may have thought.
Use a paper towel or soft, clean dry cloth and press firmly onto the stain to remove any excess oil on the surface. Be careful to blot, not wipe. Wiping will only spread the stain around.
Apply enough cornstarch to the area to cover the entire stain.
Using your fingers, rub the cornstarch into the stain briskly. Create enough friction to feel the heat.
Apply more cornstarch, as needed, and keep rubbing until all of the olive oil is drawn out of the leather.
Vacuum up the cornstarch with the brush attachment of the vacuum cleaner.
Avoid using harsh chemicals and abrasives on leather.