Hay urges the movement, which has played the song at its demonstrations, to leave his music alone.
"Down Under," which he wrote with bandmate Ron Strykert and which became a huge hit in the 1980s, "does not belong to those who try to spread xenophobia in our fantastic country," the singer writes on social media.
The song, he continues, stands "for pluralism and inclusion."
The 72-year-old, who was born in Scotland and came to Australia as a teenager, signed his message with "Colin Hay (immigrant)".
