Cancel Minecraft Realms

There is no single cancel link. Realms is cancelled through the platform account that started the subscription: the Minecraft game menu on Bedrock, your Microsoft account for Java, or a console or phone store. Your realm stays up until the renewal date.

Minecraft Realms has no page we can link to. The steps below are from their official help page.

Open Minecraft Realms’s help page

Signed up through Apple, Google Play or Microsoft?

Then Minecraft Realms cannot cancel it for you. Use the store you paid through instead.

What to expect

Buried in settings

Steps

Bedrock Edition: launch Minecraft on the device you used to subscribe, open Settings, choose Subscriptions, then Cancel next to the Realms subscription, and finish in the store you are sent to
Java Edition: cancel through your Microsoft account at account.microsoft.com/services
Bought on PlayStation, Xbox or Nintendo Switch: cancel in that console's subscription settings
Bought on iPhone or Android: cancel in Apple Account subscriptions or Google Play subscriptions