Arthur Diemer Kool (30 January 1896 – 3 October 1959) was a Dutch tennis player.

[3] He played in 15 ties for the Dutch Davis Cup team between 1920 and 1933 and compiled a 25–13 win-loss record.

Diemer Kool participated in the 1921 Wimbledon Championships where he reached the third round in the singles event in which he lost to André Gobert in four sets.

In the doubles event he partnered Christiaan van Lennep and also reached the third round, losing to Alfred Beamish and Frank Fisher.

[4] On 18 July 1918 he married tennis player Marie Bernardien de Bloeme in The Hague and they had five daughters.