Majority of the scholars of Islam consider squid and octopus to be halal (Maliki, Shafi’i and Hanbali). The Hanafi scholars say it is Makruh.

Squid and Octopus are sea creatures and Allah has made everything from the sea that is not harmful halal. Besides the exceptions named. Octopus and squid are not named in this exception. So majority of the scholars are of the opinion that both octopus and squid are halal seafood.

Octopus and squids, like fish, can be eaten without slaughtering (Zabiha).