Vancouver, British Columbia-based Flickr lets users upload digital photos from computers and camera phones, put together photo albums, and post photos to blogs, among other things.
Joanna Stevens, a spokeswoman for Sunnyvale, Calif.-based Yahoo, confirmed the deal Sunday but did not disclose the terms.
"We look forward to working with them for their innovation and product development across the Yahoo Network in the coming months," she said.
Stevens said Flickr will remain a standalone site for now. The company's employees, however, will relocate to Sunnyvale later this year.
Earlier this week, Yahoo announced Yahoo 360. The service combines a new blogging tool, along with several longtime Yahoo products, including instant messaging, photo storage and sharing, and Internet radio. It also offers tools for sharing recommendations about places to eat, favorite movies, music and so on.
Both the 360 move and the acquisition of Flickr and parent company Ludicorp Research & Development come as social networking and blogging draw increased interest from rivals. Microsoft in December added a blog product for its MSN Web service, called MSN Spaces. Google, meanwhile, owns Web log service Blogger and social networking site Orkut.
CNET News.com's Evan Hansen contributed to this report.