There are multiple ways to block someone on Instagram. You can also
view your blocked accounts list from the Instagram app, where you can choose to block other people or unblock someone on the list. People aren't notified when you block them.
When you block someone from the Instagram app, you’ll have the option to block their account, or to block their account and new accounts they may create.
From the Instagram app for Android and iPhone and Instagram Lite app for Android:

Block or unblock someone through settings
Tap

or your profile picture in the bottom right to go to your profile.
Tap

in the top right, then tap
Settings.
- Tap Privacy, then tap Blocked Accounts.
- To unblock someone on your blocked accounts list, tap Unblock to the right of their name. Tap Unblock again to confirm.
- To add someone to your blocked accounts list, tap
in the top right and search for the person you’d like to block. Tap Block to the right of their name. - To block the account and new accounts they may create, tap Block at the bottom to confirm.
- If you prefer to only block that account, tap
next to
Block [username]. Tap Block again to confirm.

Block or unblock someone through Direct
Tap

or

in the top right of Feed.
- Tap the chat with the person you want to block/unblock.
- Tap the person's name at the top of your chat.
- Tap Block/Unblock, then tap again to confirm.