U2 made their television debut as “U2” on June 1st, 1978 on the RTE program Youngline. They had been on Youngline earlier that year, in March 1978, but it was under their previous name “The Hype”.
Then in 1980 U2 appeared on the RTE program The Late Late Show, hosted by longtime presenter Gay Byrne, where they performed their of song “Stories for Boys”.
Just a year later, the band made their US television debut on the Tomorrow Show with host Tom Snyder.
Thanks Chip Beale!