Some justices worried during arguments in April that a ruling for the broadcasters could also harm the burgeoning world of cloud computing, which gives users access to a vast online computer network that stores and processes information.
But Justice Stephen Breyer in his majority opinion that the court did not intend to call cloud computing into question.
Justices Antonin Scalia, Samuel Alito and Clarence Thomas dissented.
Broadcasters including ABC, CBS, Fox, NBC and PBS sued Aereo for copyright infringement, saying Aereo should pay for redistributing the programming the same way cable and satellite systems must or risk high-profile blackouts of channels that anger their subscribers.
In Utah, U.S. District Judge Dale A. Kimball ruled in February that the controversial TV service violated copyright law and must cease operation in Utah. He also put on hold a lawsuit filed against Aereo in the fall of 2013 by local broadcasters KTVX Channel 4, KUCW Channel 30, KSTU Channel 13 and KUTV Channel 2 pending the outcome of the case decided Wednesday by the Supreme Court.
Aereo's service starts at $8 a month. Subscribers get about two dozen local over-the-air stations, plus the Bloomberg TV financial channel.
In each market, Aereo has a data center with thousands of dime-size antennas. When a subscriber wants to watch a show live or record it, the company temporarily assigns the customer an antenna and transmits the program over the Internet to the subscriber's laptop, tablet, smartphone or even a big-screen TV with a Roku or Apple TV streaming device.
The antenna is only used by one subscriber at a time, and Aereo says that's much like the situation at home, where a viewer uses a personal antenna to watch over-the-air broadcasts for free.
The broadcasters and professional sports leagues also feared that nothing in the case would limit Aereo to local service. Major League Baseball and the National Football League have lucrative contracts with the television networks and closely guard the airing of their games. Aereo's model would pose a threat if, say, a consumer in New York could watch NFL games from anywhere through his Aereo subscription.