Paul Geoffrey Allen Johnstone (30 June 1930 – 22 April 1996) was a South African rugby union wing.

[2] In 1952 he returned to the United Kingdom and entered St John's College, Oxford, to read law.

For many years he was general manager of South African Breweries in Salisbury, Rhodesia (now Harare, Zimbabwe).

[2] There was talk of him being dropped to the university second team, and he was injured in his second appearance of the trial where there was doubt that he would be able to play again for some time.

Johnstone next played in the third game against a joint Pontypool/Newbridge team (scoring another try), before being moved into the centre position in an encounter with Llanelli.

[8] Johnstone was criticised for some poor defensive work, with his tackling sometimes high and ineffective, but he started the scoring with a try late in the first half.

The Wales game was the most highly anticipated of the tour, with the match being hailed as the 'game of the century' and as 'for the rugby championship of the world'.

Johnstone played against Newport and Midland Counties, scoring a try in the former, before he was selected for the last game in Britain, an encounter with the Barbarians.

On the day of the match, South Africa, through injuries, were without both fly-halves, Dennis Fry and Hannes Brewis.

Johnstone was given the fly-half role despite having last played in that position over three years previously in an encounter between Natal and Transvaal.

[13] The South African's reacted by bringing Keevy in at fly half and putting Johnstone back out at his favoured right wing position.

[18] On their return to South Africa, Johnstone received a letter from 'Danie' Craven, the tour leader and coach, stating that "You were the most improved player in the team".

As well as the club and representative games, South Africa played six Tests, two against Australia and four against the New Zealand 'All Blacks'.

Johnstone played in the first Test against Australia, in his favoured position of right wing; South Africa won 9–0.

Despite the loss, Johnstone was back for the second Test against the All Blacks, this time a win for South Africa.