.... You need to double check which one but some of the Canon lens hoods and also
Fotodiox hoods are apparently a good fit and a very practical substitute for the fancy Olympus ones which too easily lose their tiny ball bearing mechanisms. Canon hoods aren't cheap-as-chips but they are cheaper than the OE. I do like the Olympus slide-back-over-the-lens feature though as it's very useful when packing - I don't often change filters.
The hood on my Olympus 40-150mm Pro got knocked on a rock while I was changing batteries during a surfer photography session and performed its own teardown into three separate components and flying tiny ball bearings surfing the sandy beach!! It is actually a very common problem.
View: https://www.youtube.com/watch?v=yiktE5yA17M