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
Shira Banki, 16, died on Sunday of stab wounds sustained when an ultra-Orthodox Jew attacked a Gay Pride parade in Jerusalem.
HSBC has reported a 10% rise in profits for the first half of the year - boosted by bumper profits in Hong Kong.
Barnado's has received £3 million to tackle child sex abuse in Rotherham, nearly a year after the Jay Report was released.