The decision was taken at a board meeting on Thursday afternoon, and ends the former defender's 17-month reign in charge at Glanford Park.
He was brought in to replace Ian Baraclough, who was sacked after a 3-0 home loss to Preston, now he has suffered the same fate.
His last match was not Tuesday's 3-2 defeat to the same opposition on his own turf, but Saturday's 3-0 reverse at the hands of MK Dons.
Knill leaves with the Iron in the League One relegation zone, with 10 points from their opening 15 games.
Source: Iron-Bru.net
Source: FOOTYMAD
