It'd be in your theme code, you might want to look into your collections.liquid or product.liquid and see if they're displaying the product.title for each collection production. I wouldn't mess around with your website code if you don't have an idea of what you're doing. It could really mess things up.
You can always hire out help.
What exactly do you mean by catalog page? As far as I can see the products' titles are showing up all over the website. Can you send the specific link where you are experiencing the issue, please