The disclosure provides a new and distinct watermelon variety NUN 31707 WMW as well as seeds and plants and fruits thereof. NUN 31707 WMW is a triploid, crimson sweet type watermelon variety, comprises resistance to Colletorichum orbiculare Race 1 and Fusarium oxysporum f. s.p niveum Race 1. The fruit of watermelon variety NUN 31707 WMW is round large and is seedless.