Sanath Jayasuriya(SriLanka) scored 50 off 17 balls against Pakistan in 1996 which is the fastest 50 in limited overs cricket.
If you also consider Twenty20 Internationals (which is indeed a form of Limited overs cricket), the record is currently held by Yuvraj Singh (India), who scored a memorable 50 off just 12 balls against England in 2007 during the Twenty20 World Cup.
Brendon McCullum
Yuvraj Singh of India has scored the fastest fifty in t20 cricket off 12 balls against England in 2007 ICC T20 World Cup.
it will yuvi the man Yuvrajsing which scores 50 from 12 balls with six trick of six
F. M. Jackson has written: 'A fifty years record of the Bowdon Cricket Club' -- subject(s): Bowdon Cricket Club
sanath jayasuriya is made the fastest fifty on ODI
sanath jayasuriya made the fastest fifty
By Minutes : M Ashraful 27 minutes vs India By Balls: J Kallis 24 Balls vs Zimbabwe
Ireland. Kevin O'Brien 113 off 63 balls England vs Ireland in the 2011 Cricket World Cup
Shahid Afridi made the fastest fifty in five year.
sanath jayasuriya made the fastest fifty in the one day international.
Sanath Jayasuriya made the fastest fifty in ODI.
Fifty years ago Australian cricket teams had eight balls in an over.