Jan-Ove Waldner, in Sweden commonly J-O Waldner or simply mononymously as J-O, is a Swedish former professional table tennis player. He is often referred to as "the Mozart of table tennis." A sporting legend in his native Sweden as well as in China, he is known in China as 老瓦 Lǎo Wǎ 'Old Wa' or 常青树 Cháng Qīng Shù 'Evergreen Tree', because of his extraordinary longevity and competitiveness.