Fastest Pitch Ever Thrown
I think it was Chapman
You're right! The fastest pitch, recognized by MLB and not somebody's recollection, was on September 25, 2010 at Petco Park in San Diego by Cincinnati Reds left handed relief pitcher Aroldis Chapman. It was clocked at 105.1 miles per hour.
Chapman 107 MPH
I think it was Bob Feller 115
Chapman 105 mph
Yes, you are right. Aroldis Chapman has the record for the fastest pitch ever at 105 mph. It might have been Walter Johnson, but there weren't any radar guns back then.
I think it was 106 mph
The greatest reliably recorded speed at which a baseball has been pitched is 100.9 mph by Lynn Nolan Ryan (California Angels) at Anaheim Stadium in California on August 20, 1974.http://www.baseball-almanac.com/recbooks/rb_guin.shtml