Karaniya Metta Sutta is translated by Bhikkhu Nyanadassana. This is a popular poem-form speech that is one of the most well-known, referenced, and performed in Theravada Buddhist countries. The title Metta Sutta appears in the Pali Canon's Khuddakapatha and Sutta Nipata.
This particular Metta Sutta is generally known as Karaniya Metta Sutta to distinguish it from other 'Metta-suttas' in the Pali Canon since its opening stanza begins with the Pali term Karaniya.