Hastings has played for Watsonians, London Scottish, Cambridge University, Scotland and the British and Irish Lions, winning 61 caps for Scotland, 20 as captain. He captained the Lions durng their tour of New Zealand in 1993.
 
He made his Scotland debut in 1986 against France and was a central figure in Scotland’s 1990 Five Nations Grand Slam. He has scored a total of 667 international points for Scotland, meaning he is at the time of writing the third all-time points scorer in the history of the Scottish side.