Parkwood Springs, Sheffield born inside forward Ernie Islip began his football career with local club Sheffield Douglas before turning professional with Second Division Huddersfield Town in 1911, making his Football League debut at Bristol City in November 1913. He played both sides of the First World War for Town, but he only played 3 times (due to injury) as the club gained promotion from the Second Division in 1919-20, but he was fit enough to play in the 1920 FA Cup Final which Huddersfield lost 1-0 to Aston Villa at Stamford Bridge, and he went one better in the 1922 FA Cup Final, this time he was on the winning side as Huddersfield beat Preston North End, against whom Islip had scored a hat-trick in a 6-0 win in a League game a week earlier, again at Stamford Bridge. He also played as Huddersfield beat Liverpool 1-0 in the FA Charity Shield match that May.
He was The Terriers’ leading League scorer with 15 goals in the 1921-22 season but after 52 goals in 173 appearances for Huddersfield Town, Islip was transferred to Birmingham for a fee of £1,500 in November 1923, and in his first full season at St Andrews he was Birmingham’s joint leading scorer, but the prolific partnership between George Briggs and Joe Bradford left him on the sidelines from 1925.
He moved on to Bradford City for a fee of £400 in the 1927 close season after 24 goals in 89 appearances for The Blues, spending one season in the Third Division North but scoring only once in 6 appearances. He had short spells at non league Kidderminster Harriers and Ashton National before returning to The Football League with Wrexham in 1928-29, his only goal in 14 appearances coming on his debut, before retiring in 1929.