Byrne won a bronze medal for Ireland at the 1956 Summer Olympics in Melbourne, Australia, in the lightweight division.

However, a fundraising campaign under the banner of "Send Byrne to Melbourne" was created, and it raised £653 for the purpose from local businesses in Drogheda.

[citation needed] Byrne carried the flag for Ireland at the opening ceremony and was the captain of the Irish boxing team.

He beat opponents from Czechoslovakia and United States before losing in the semifinal on a split decision to Harry Kurschat of Germany.

[2][3] A few months later, he showed what might have been when he beat the eventual Gold Medallist, Dick McTaggart, in an Ireland-England International at the Royal Albert Hall.