Steinhafel, who worked at the company for 35 years, will be replaced by Chief Financial Officer John Mulligan.
"The last several months have tested Target in unprecedented ways," Steinhafel wrote in a letter to the company's board of directors. "We have already begun taking a number of steps to further enhance data security, putting the right people, processes and systems in place. With several key milestones behind us, now is the right time for new leadership at Target."
Last December's data breach, which compromised the payment or personal data of more than 110 million customers, cost Target at least $61 million to fix, hurt holiday sales, and caused the company's credit rankings to be downgraded.
[Image via AP]