Harry Robinson came through the grades with Pentyrch before joining Blues South U16s. The young wing burst on to the domestic scene in Wales in the 2010/11 season. He played for both the Wales U18s and Wales U20s then, in the same season, made his senior debut with Cardiff Blues.
In January 2012 he was called into the Wales 35 man senior squad for the training camp in Poland prior to the 2012 Six Nations Championship. Robinson scored his first international try in his debut match for Wales verses the Barbarians on 2 June 2012 at the Millennium Stadium.
He was a member of the Wales touring side to Australia and played against the Brumbies in Canberra but didn't get a game in the three-Test series against the Wallabies.
In January 2013 he was selected in the Wales Under 20 squad for the 2013 Under 20 Six Nations Championship. Robinson was also named included in Wales’ summer tour of Japan.