Konstantinos Karamitroudis (born 12 September 1980), better known as Gus G, is a Greek heavy metal guitarist. He currently plays with his band Firewind. He has also played in Mystic Prophecy, Nightrage, Arch Enemy, Dream Evil and Ozzy Osbourne's band.
In 2009, Gus was sent an email invitation from Ozzy Osbourne's management to learn several songs and take a flight to Los Angeles to audition for the role of guitarist in Ozzy Osbourne's backing band. After jamming with the band, Gus was "asked on the spot to come back and perform a concert with Ozzy a couple of months later". Soon thereafter it was announced that Gus G would be taking the place of lead guitarist for Ozzy Osbourne. Ozzy had decided to part ways with longtime guitarist Zakk Wylde, because he thought his music was beginning to sound too much like Zakk's band Black Label Society. Gus's first live appearance with Ozzy was at the BlizzCon 2009.