This study aims to analyze the responsibility for criminal defamation in social media in the digital era. The results showed that defamation or insults carried out through social media can be categorized as an act of Cyber Crime, because it has violated the provisions of general criminal offenses as in Article 331 of the Criminal Code, can be imposed for cases of defamation using the internet media. There are six types of defamation in the Criminal Code, namely 1) Blasphemy, 2) Defamation with letters, 3) Slander, 4) Mild insult, Criminal liability for criminal defamation, it needs to be seen from the article first, in relation to what mistakes are emphasized based on Criminal Code, Law No. 40 of 1999 concerning the Press, Law no. 32 of 2002 concerning Broadcasting, and Law Number 19 of 2016 concerning Amendments to Law Number 11 of 2008 concerning Information and Electronic Transactions (UU ITE).