See related answer below.
i think it is greg rusedski with a 239.8 km/h
For the girls Venus Williams. 127 mph was the speed.
128 is her fastest at wimbledon Some sources says (e.g. wikipedia) that V. Williams fastest serve stroke was 130 mph (210 km/h)
the fastest serve was 153 miles an hour
Samuel Groth has hit the fastest serve at 263 km/h.
The fastest racquetball serve was recorded by Egan Inoue at 191m.p.h. Brian Fredenberg has the second and third fastest serves at 187m.p.h. and 186m.p.h.
on 24th June 2009 I watched a 141MPH from Ivo Karlovicagainst Steve Darcis and he consistently served over 135MPH ! He also second served at around 120MPH throughout and one second serve was 126MPH - that must be a record?
138 Miles Per Hour.