It caps a remarkable turnaround for the Ashton Gate side, who were struggling down at the bottom until January, and Johnson is proud of his men and predicts bigger things from them in the next campaign.
"The improvement has been incredible. We are not the same side as when I took over," Johnson said. "My aim when I took charge was to put the club in a position where we have a solid foundation to be able to compete next season, and I think we've done that.
"The players were fighting for their place for next season's promotion push and I think that's been reflected in our performances and results over the last few months. They had to show that they want to be part of things here and, credit to them, they have.
"That can only be good for our cause and I fully expect us to continue in the same vein next season and be up challenging at the top of the table."