It's in An English Book of Light Verse by Guy Boas (Macmillan & Co. Ltd., 1944), page 273.

It was also in Punch in 1926.


THE INCORRIGIBLE
Guy Boas

He didn't like authority; O'Kelly was his name.
He wouldn't do a stroke of work or play a single game.
They did their best to make him, but it wasn't any use.
He resisted all coercion and was deaf to all abuse.

Their efforts to instruct him he persistently ignored.
He wouldn't look at anything they wrote upon the board.
He wouldn't construe Caesar or attempt a simple sum,
And when they asked him questions he pretended he was dumb.

He wouldn't rise for early school, he wouldn't go to bed,
He wouldn't answer "Adsum" when the call-over was read ;
He wouldn't blow the organ, and he wouldn't write out lines,
And when he lost the lib'ry books he wouldn't pay the fines.

He wouldn't cap the masters and he wouldn't call them "Sir;"
The prefects tried to make him fag but he declined to stir ;
He was cheeky to the matron, he was saucy to the maids.
He was very insubordinate on A.T.C. parades.

He wouldn't keep in bounds, and they discovered him one day
Very early in the morning breaking out to run away.
As this clearly was the moment their authority to show,
The Head expelled O'Kelly, but O'Kelly wouldn't go.


[I think this is complete, but I'm not sure; I had to work some special mojo to extract it from a book that Google classifies as "snippet view."]