Compared to other social networks, Reddit is a bit more barebones in terms of features and therefore also in terms of privacy settings. Here’s a handy list of the things you can do to harden your Reddit account.
Content visibility: disable. Here you can select whether or not
posts to this profile can appear in r/all and your profile can be discovered in /users.
Active in communities visibility: disable. If enabled, it shows which communities you’re active in on your profile.
Show up in search results: Disable.
Personalize all of Reddit based on the outbound links you click on: Disable.
Personalize ads based on your Reddit activity: Disable.
Personalize ads based on information from our partners: Disable.
Personalize ads based on your activity with our partners: Disable.
Personalize recommendations based on your general location: Disable.
Personalize recommendations based on your activity with our partners: Disable.
Use two-factor authentication: Enable!
Manage third-party app authorization: Review periodically, disable app accesses as needed. Less access means less potential data leaks.
Online Presence Indicator
Announced in March 2021, this new and terrible feature is on by default. Click your username on top right and disable (“Hiding”). Check periodically to see if it has switched back on automatically.