1900 - 1945:
1900/01 saw Queen's Park join the professional leagues, and although there were two divisions, there was little danger of them being relegated, as promotion/relegation was decided by voting rather than league placings, and with the large travelling support of many thousands (as well as a share of the gate from the many thousands who would turn up at Hampden every second week), most clubs in the top division were more than happy for Queen's to stay in the top division.
That is not to say that Queen's relied on this to stay up; although they did fall back on this escape hatch five times up to 1920/21, they were usually comfortably above this zone, and managed top half finishes a couple of times in this period.
To take advantage of the increasing crowds the game was attracting, Queen's opened the third Hampden Park in October 1903, with a 1-0 league win over Celtic. Their old ground was taken over by Third Lanark, renamed Cathkin Park, and was used by Thirds until their demise in 1967.
However, the advent of automatic promotion and relegation saw Queen's go down in 1921/22 in second bottom place. The stay downstairs was for the shortest possible period, Queen's coming straight back up as champions of Division two in 1922/23.
They were to retain their place in the top division (on their own merits) until the last season before the War, and in the late Twenties a great team came together that gave Queen's their best seasons since joining the league. The likes of Jack Harkness, "Mutt" McAlpine and Dougie McLelland took Queen's to a 5th place finish out of 20 teams, the club's highest ever finish in their league history.
The same team also beat Arthurlie, Morton, Kilmarnock and Partick Thistle on their way to the semi-final of the Scottish Cup where they lost out by the odd goal in three to Celtic. That match in 1928 remains the last time Queen's have reached the semi-finals of the Scottish Cup, and until the run to the semi-finals of the Challenge Cup in 2002/03 it had been the last time we had reached the semi-final of any competition.
The club's First Division status was maintained throughout the thirties, but as war approached Queen's finished second bottom in 1938/39, and commenced the following season in Division Two. However, four games into the season (and with Queen's unbeaten) the league was stopped when the War started, and was replaced by the Southern League in October of 1939.
That was where Queen's stayed until the end of the War in 1945, usually finishing in the lower half of the table.