The attack took place on February 9 when two men on pushbikes approached a man outside the Poundshop store in St Sepulchre Gate and stabbed him in front of shocked shoppers.
Both the victim and the attackers fled the scene before police arrived.
A South Yorkshire Police spokesman said: “Officers in Doncaster are appealing for witnesses and information following a stabbing in Doncaster town centre.
“We received a call at 12:46pm on 9 February for reports of a stabbing at St Sepulchre Gate.
“The victim suffered non-life threatening injuries. The victim and the men left the scene.
Enquiries are ongoing and an investigation is underway, and officers are keen to hear from anyone who may have witnessed the attack or have information that can assist with their enquiries.
If you can help please call 101 quoting incident number 431 of 9 February.