Disney's entrance, which comes after months of negotiations, means that three of the four major U.S. broadcast networks now have stakes in Hulu: NBC, News Corp's Fox and Disney's ABC. Only CBS Corp is absent.
Hulu officials declined to provide financial details on the deal on Thursday. A source directly involved in the deal, who did not want to be identified because all sides in the deal decided that the terms would be confidential, put Disney's stake at 30 percent, the same as the other networks.
Disney will get three seats on the 12-member board, the same as News Corp and NBC Universal.
Hulu has emerged as one of the most popular online video destinations since its launch in 2007. Though it still lags Google Inc's YouTube, some 380 million videos were viewed on Hulu last month, up 14.3 percent from February, according to market research firm comScore. It is now among the top three online video sites in the United States.