He won fourteen caps for Ireland and was selected to captain the British Isles 1910 tour of South Africa, and played in two of the test games.

Smyth first played for Ireland in 1908, in the Home Nations Championship against England at Richmond's Athletic Ground.

With the match played at Lansdowne Road, the Irish beat the Scottish team in a game which was notable as the last game for Scotland's David Bedell-Sivright, the British Isle's captain of the 1904 campaign to Australia and New Zealand.

Smyth's next and last score for his country was in a 3–0 win at Lansdowne road versus England, when the Harlequin centre Frank Stoop's poor clearing kick led to Smyth scoring the only points of the game when he took the ball over the line for a try.

Note 9: Michael Owen captained the Lions in the first tour game, the test vs. Argentina in Cardiff.