The Championship's bottom club have dismissed their manager after a 4-0 defeat to Leicester City at Ashton Gate on Saturday saw them fall six points from safety
The loss was the club's third in a row and leaves them bottom of the Championship table with just 22 points from 26 games.
Robins managing director Jon Lansdown told the club's official website: "This is a decision we felt we had to make for the good of the football club.
"Derek has been a pleasure to work with; he’s disappointed but he understands the decision.
"We want to give ourselves the best possible chance of getting out of the situation we are currently in and we’ve got 20 games to do that."
McInnes successfully guided City to safety after taking charge at Ashton Gate in October 2011, but a poor first half to the 2012-13 season sees the club sit six points from safety.
Assistant manager Tony Docherty will take training on Monday.