[3][4][5] Willis was educated in England before boarding at The Cathedral School, Llandaff, and at Pangbourne Nautical College in Berkshire.

During this period Willis linked up with fellow Rhondda born Cardiff player, Cliff Morgan, a relationship that would last throughout their club and country careers.

Willis was chosen alongside team mate Billy Cleaver to face England at Twickenham in the opening game of the 1950 Championship in front of the largest crowd ever seen to date at the stadium.

With tries from Thomas and Ken Jones Wales ran in easy winners after subduing the Scottish pack in the first half of the game.

After his performance during the Championship, Willis, along with Cardiff backs Cleaver, Jones, Williams and Matthews, was chosen for the British Lions in their 1950 tour of Australia and New Zealand.

Willis was back for all four matches in the 1951 Five Nations Championship again under the captaincy of John Gwilliam, who had led the team to their Grand Slam victory the previous year.

In the 1953 Championship he was considered not fit enough to face England, and was forced to leave the field when he injured his shoulder against Scotland.

As in 1951, Willis was chosen to face another touring team on three occasions in 1953, when Cardiff, Wales and the Barbarians played the All Blacks.