Click on the contact you want to delete to open a chat with them.
Click on their name at the top of the chat to open their profile.
Click the three-dot menu (⋮) in the top-right corner of their profile.
Select "Delete Contact" and confirm.
Note: Deleting multiple contacts at once is generally easier on mobile.
2. Preventing Unwanted Contacts from Appearing (Stop Syncing)
This is crucial if you want to stop Telegram from telegram number database automatically adding people from your phone's address book or if you've already deleted synced contacts but they reappear.
Open Telegram.
Go to Settings.
Tap on "Privacy and Security".
Scroll down to the "Contacts" section.
Toggle "Sync Contacts" OFF. This prevents Telegram from continuously uploading your device's address book and adding new users from it.
"Delete Synced Contacts" (Clear Cloud Data):
In the same "Contacts" section (within Settings > Privacy and Security), tap "Delete Synced Contacts".