Gallacher was born in Bathgate, Scotland. He took up golf at the age of eleven. In 1965 he won the Lothians Golf Association Boys Championship. He won the 1967 Scottish Amateur Open Stroke Play Championship and turned professional the same year.

He won the Sir Henry Cotton Rookie of the Year award in 1968. His first professional wins came in 1969; a pair of them in Zambia and another pair in Europe in the equivalent of European Tour events. (The European Tour wasn’t established until 1972.) He finished 1969 as Order of merit winner earning the Harry Vardon Trophy.

In 1969, at the age of 20, Gallacher became the youngest man to represent Great Britain in the Ryder Cup up to that time. This record was subsequently beaten by Nick Faldo and others. He went on to play in the Ryder Cup eight times and was non-playing captain of the European Team in 1991, 1993 and 1995. All three of those matches were very close; Europe lost the first two but won the third.

CUT = missed the half-way cut (3rd round cut in 1969 Open Championship) “T” = tied Note: Gallacher never played in the U.S. Open or the PGA Championship.

He accumulated ten wins on the European Tour between 1974 and 1984 and finished in the top ten on the European Tour Order of Merit five times between 1972 and 1982, with a best placing of third in 1974.

After turning 50, Gallacher played on the European Seniors Tour. His first senior win came at The Mobile Cup in 2002.

Gallacher also wrote a column for Scottish golf magazine bunkered from 1998 until 2008. In August 2014, Gallacher was one of 200 public figures who were signatories to a letter to The Guardian opposing Scottish independence in the run-up to September’s referendum on that issue.