Open Telegram
Go to Contacts
Select the contact you want to delete
Open the contact’s profile
Tap Edit
Tap Delete Contact
Confirm deletion
On iPhone
Open Telegram
Go to Contacts
Tap the contact
Tap Edit
Tap Delete Contact
Confirm
On Android
Open Telegram
Tap the menu
Open Contacts
Tap the contact
Tap the three dots
Tap Delete Contact
Confirm
To remove a synced contact from your phone too
Delete the contact from your phone’s address book
Open Telegram
Refresh contacts if needed