The fastest tennis serve ever recorded was hit by Australian player Sam Groth in Busan, South Korea in 2012, clocking in at a whopping 263.4 km/h or 163.7 mph. However, given the fact that the serve was recorded at a ITF Challenger level event, the ATP (Association of Tennis Professionals) does not officially recognise it as the fastest serve ...
https://tenniscreative.com/fastest-tennis-serve