How do I delete my Amazon order history so others on the account can't see what I bought?

Straight answer: Amazon doesn't let you permanently delete an order, they're kept for legal, warranty and tax reasons. What you CAN do is 'Archive order': Returns & Orders > find the order > 'Archive order' (sometimes under a three-dot or 'more' menu). Archived orders leave your main list and move to a separate Archived Orders page, so a casual look won't show them. Limits: it's hidden, not truly private (someone who knows to check Archived Orders can still find it), and there's a cap on how many you can archive. For real privacy on shared stuff, a separate account or an Amazon Household profile is the cleaner fix.

You can't truly delete, only 'Archive order', which moves it off the main list to an Archived Orders page. Hidden from a glance, not gone, and not truly private from someone who digs.

If privacy matters that much, stop sharing one login. Amazon Household gives each person their own profile and order history under one Prime, so nobody sees anyone else's purchases.