They recruited 3 key players from their Polish rival being Izydor Sierocinski, Jerry Demczuk and Stanislaw Czerkawski for the clearance fee of £2.

The club recruited John Kerr from Port Thistle and In its first season in Division One Polonia took out another Premiership, losing only 2 of its 18 matches.

The former Division 1 player with Gwardia Warsaw Eugene Nowak at the age of 30 was appointed the player-coach of Polonia.

A number of Polonia players including Eugene Novak revelled in playing against Manchester United on 27/6/67 against the likes of Denis Law, Bobby Charlton Nobby Stiles and Brian Kidd.

The arrival of three more of Polonia's imports namely Zdebel, Cygan and Poloczek saw the club win the First Division Premiership and the Federation Cup.

In 1983 Adam Karpinski arrived from Poland and the senior team finished third, Reserves fourth and the Juniors again won their Premiership.

In 1988 the club contracted Professional Coach Z Gutowski and three further players from Poland-M Niewiadomski, P Wieczorek and E Lonka.

The club Chairman Greg Sierocinski, then recruited former Adelaide City player and former Socceroo Joe Mullen, who just finished coaching Green Gully in the Victorian Super League.

On 1 September 2011, it was announced that the new senior team coach for the 2012 season would be club legend John Kosmina.

On 11 August 2012 the club won the FFSA Super League premiership finishing top of the table after defeating Adelaide Comets 1–0 at Polonia Reserve.

On 13 September 2014 the club was crowned champions of the 2014 National Premier Leagues South Australia by defeating North Eastern MetroStars SC 2–1.

[4] The clubs recent success continued when they lifted the 2015 FFSA Federation Cup trophy after defeating Adelaide City 2–0 in the final with both goals scored by striker Andreas Wiens.

At the conclusion 2017 FFSA season, and after placing 4th on the league table Croydon qualified to take part in the 2017 finals series.

Courtesy of two-second half goals from strikers Paul Radice and Shaun McGreevy the club claimed its second NPL SA championship title with a 2–1 win.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.