In many states, carrying unconcealed guns in public is legal.
Target spokesman Molly Snyder said the move is a "request and not a prohibition."
"We don't have any plans for proactive communication to guests beyond what Target leadership shared today," she added.
Target does not sell guns in its stores or on its website.
Target Corp. made the announcement as it faced pressure about its policy on the "open carry" of firearms in its stores. A group called Moms Demand Action for Gun Sense in America gathered nearly 400,000 signatures for a petition asking Target to prohibit shoppers from carrying guns into its stores.
The group has said it is responsible for getting several chains, including Chipotle, Starbucks and Jack in the Box, to to make similar moves. It introduced the campaign after gun rights groups carrying loaded rifles frequently gathered in Target stores including Texas, Alabama and North Carolina to demonstrate in support of "open carry" laws.
"Such positive safety changes made by some of our country's leading retailers are proof of the influence of women and mothers," said Shannon Watts, founder of Moms Demand Action for Gun Sense in America. "As we look toward election season, we hope our legislators are taking notice that when women and mothers collectively raise our voices and soon cast our votes, we are determined to leave an impact."
The Minneapolis company's stock added 36 cents to $58. 73 in Wednesday mid-day trading.