The vehicle came under attack on Balby Road - with passengers narrowly avoiding injury after broken glass showered onto them after an unknown projectile shattered the window.
Teenagers Morgan Osborne and Chelsea Swindells were among those travelling on the Stagecoach bus when it came under fire on Monday night.
Said Morgan, 19: "We were just travelling home when someone shot at the bus.
"We were just sat there when suddenly the window came through and glass was going everywhere.
"It left us pretty shook up."
The pair were travelling through Balby on the 221 service which connects Rotherham and Doncaster Interchange at about 9.40pm when the incident happened.
He added: "We were heading into town. No one was injured.
"But I saw the reaction of us and other people - we were all shook up.
"The driver told us to sit on the other side and he carried on driving in to town."
Matt Davies, managing director of Stagecoach Yorkshire, said: “We can confirm that a window was damaged on our service 221 on Monday evening on Balby Road.
“Having reviewed CCTV it appears that the bus was struck by an object which caused the window to crack and later shatter. No-one was injured, and our driver ensured all passengers alighted safely and boarded an alternative bus.
“All incidents of vandalism, which we suspect this was, are logged by our staff and reported to the Police.”