Di Canio recently replaced Martin O'Neill at the Stadium of Light and has been charged with the task of keeping Sunderland in the Premier League.
The Italian presided over a stunning 3-0 win at local rivals Newcastle United on Sunday and Johnson has praised Di Canio's early impact.
"The manager gives everyone confidence in the team," said Johnson, who scored in the victory at St James' Park.
"He speaks to you individually and has spoken to me about things such as keeping the team's shape, as he wants it to be perfect. He believes if the team have a good shape then we'll score.
"Our shape on Sunday was excellent and we played off that. Newcastle just couldn't live with us when we attacked.
"I don't think there was a better way for the manager to win over the fans but they would probably have loved him anyway. Anyone with that amount of passion and love of the game is hard not to like."
The derby win lifted Sunderland up to 15th in the table and Johnson expects a fight to the finish in the battle for survival, with several clubs still in relegation danger.
The winger added: "When you look at the league table now it is not quite as scary as it was and we are hopefully going to go from strength to strength.
"There are a few teams that could still get dragged into the relegation fight.
"I don't think anyone down there can believe they are out of the woods, certainly when you look at the fixtures that are coming up for some of them.
"It won't be between Sunderland and Newcastle who goes down. There are a lot of teams that could get dragged into it. There are five games to go and a lot of points still to play for."