George Jan Kooymans (born 11 March 1948) is a Dutch guitarist and vocalist. He is best known for his work with the Dutch group Golden Earring.^[1] Kooymans wrote "Twilight Zone", the group's only Top 10 Pop Single on the US Billboard Hot 100, which hit No. 1 on the Billboard Top Album Tracks chart.^[2]

Kooymans also wrote and produced for other artists. In 2017 and 2018 he released two albums as a member of Vreemde Kostgangers (Strange Boarders), a Dutch-language supergroup he formed with Henny Vrienten (bass player of the band Doe Maar) and singer-songwriter Boudewijn de Groot.

Kooymans is married to Melanie Gerritsen, the younger sister of Golden Earring bassist Rinus Gerritsen. Kooymans primarily played a Gibson Les Paul, a Gretsch 6119, a Fender Stratocaster, a Gibson Marauder, a Gibson SG, a Yamaha SG2000, several BC Rich guitars, a double cutaway Gibson Melody Maker and a Gibson Firebird, with his primary amps being a Roland Jazz Chorus, a Vox AC30 amp, and a Fender Twin Reverb. ^{[3] [4]}

In February, 2021, Kooymans announced that he was suffering from amyotrophic lateral sclerosis (ALS) and would retire. Shortly afterward, Golden Earring announced they would disband.^[5]