Target, which has over 1,900 outlets in the US, made the decision after a man drew a gun in a fight over trading cards outside a store in Wisconsin.
"The safety of our guests and our team is our top priority," the company said in a statement to US media.
Sales of trading cards have rocketed amid the pandemic.
The suspension of in-store sales is temporary, the company said, adding that online sales are not effected.
Walmart, a top competitor to Target, says they have also seen increasing demand, but do not currently have plans to block sales.
A fight broke out in a car park outside a Target in Brookfield, Wisconsin, on 7 May, after four men allegedly assaulted another man over sports trading cards, reports the Milwaukee Journal Sentinel.
The victim, who had a licence to carry a concealed gun, ended the fight by drawing his weapon, police say.
No shots were fired, and the four men ranging in age from 23 to 35 fled and were later arrested.