Kirknewton, Lothian born centre half Peter Gaffney (nb he is also quoted as having been born at Straiton, near Loanhead, Lothian) began his football career with Loanhead Mayflower prior to the First World War and played for Dalkeith Thistle. He entered senior football with Bo’ness after the War, playing for them at the start of the 1919-20 season but he soon joined Hamilton Academical later in 1919 and spent two seasons at Douglas Park before a move to Alloa Athletic in 1921. He spent a single season with The Wasps joining Dunfermline Athletic in 1922, from where he ventured south of the border to join Third Division (North) club Doncaster Rovers in June 1923. He made his Football League debut in a 2-2 draw at Southport in November that year, and his only other appearance for Donny also finished a 2-2 draw, a week later at home to Barrow.
Gaffney moved to Midland League club Denaby United before the year end and returned to Football League action joining Barrow in June 1924, where he made 21 appearances for The Bluebirds during the best part of their 1924-25 campaign, being transferred to New Brighton in March 1925. After losing his place the same October, he returned to the New Brighton first team deputising at centre forward in March 1926, where he scored a couple of goals in wins over Hartlepools United and Rotherham United, but he wasn’t retained and joined Coventry City in June 1926 after 3 goals in 18 appearances for The Rakers.
He managed just 3 matches for Coventry in their 1926-27 campaign, scoring in an FA Cup defeat at Lincoln City, and after joining Ashington in July 1927 just a single appearance in a heavy defeat at Halifax Town that September. He then spent some time on the books at Torquay United without making their first eleven but before the year end had joined Southern League club Aldershot, for whom he appeared in an FA Cup tie at Peterborough & Fletton United that December, when they lost 2-1. Aldershot was his last known club before leaving the professional game.