The profit, achieved effectively by the sale of Robin van Persie to Manchester United, also accompanies an increased figure of £123.3m in cash reserves, up £7m.
The figures are for the half year to the end of November 2012.
Arsenal chairman Peter Hill-Wood said: "Our ability to compete at the top of the game here and in Europe is underpinned by our financial performance which gives the club strength and independence.
"Our desire is to make everyone connected with Arsenal proud of the club. We know that comes through winning trophies but also through the way we do things and that will remain our constant guide."