Cyber attackers have accessed eBay customers' names and contact details, the company said in a statement.
eBay said: "The database, which was compromised between late February and early March, included eBay customers’ name, encrypted password, email address, physical address, phone number and date of birth.
"However, the database did not contain financial information or other confidential personal information."
The online auction site said evidence of the hack was first detected about two weeks ago, but it was now making the announcement after "extensive forensics".
More top news
Those who wear face veils in public are liable to a £664 fine and a suspension of social benefits.
The extent of last winter's floods has been revealed after a survey by the Local Government Association
Jackie Walker, vice-chair of the pro-Corbyn group Momentum, was suspended over comments shown on a leaked video.