Having scored in each of his last four league matches, Volland's strike lifted his team to seventh in front of Germany assistant coach Hansi Flick at Hoffenheim's Rhein-Neckar Arena.
Striker Anthony Modeste gave Hoffenheim the lead just before the break, then provided a superb through ball for Volland to pounce on, turn the defence and hit the bottom right-hand corner.
"It was a great pass from Anthony, things are going well for me, I worked hard in pre-season which gave me confidence," Volland said.
"I just want to have a good season with Hoffenheim and anything else would just be a bonus," he added when asked about a possible call up to Joachim Low's senior Germany side.
Gladbach pulled a goal back when Swedish striker Branimir Hrgota powered through the Hoffenheim defence 15 minutes from time, but the defeat left Lucien Favre's side in mid-table.
Later, bottom side Eintracht Braunschweig picked up their first point of the season after four defeats with a 1-1 draw at Nuremberg, with the hosts also in the bottom three.