As of 18 May 2013, the fastest 800m run (or 800m world record) was done at the 2012 Summer Olympics in London, United Kingdom, on the 9th of August by David Rudisha of Kenya. Rudisha ran the 800m in 1:40.91, breaking his own world record by ten hundredths of a second (previously 1:41.01).
You can watch his awesome run in the video in the related links section.
The fastest 800 dash by a male is:
1:41.01 by David Rudisha of Kenya
The fastest 800 dash by a female is:
1:53.28 by Jarmila Kartochvilova of Czechoslovakia
The WR is currently 1:41.11
1:41.11 - Wilson Kipketer (DEN)
1:41.01 by world record holder David Rudisha of Kenya.
the time usain bolt the fastest man in the world was 9.58 seconds in the 100 meter sprint
The fastest time ever for the Men's 100 meter is 9.63 seconds. This was accomplished by Usain Bolt who has been dubbed the fastest man alive.
Usain Bolt was clocked at 9.69 seconds for the 100 meter race at the 2008 Olympics in Beijing. He is regarded as the fastest man in the world.