Apple is tipped to launch the TV later this year and the watch will be used to give commands to the TV.
The Wall Street Journal reports that the application was made in Japan on June 3 and made public on June 27.
The Guardian claims the name of Apple's iPod was first discovered from trademark filings ahead of its launch in October 2001 - though it trampled over Cisco's "iPhone" trademark in 2007, when it launched its phone that January. The two companies later came to an agreement shortly after the 2007 CES show.
According to sources, Apple has a huge team of engineers working on the iWatch project, with companies in Japan that specialise in miniaturisation being consulted on miniature electronic components. Tim Cook, Apple's chief executive, didn't rule out the idea of a wearable iWatch when he appeared at the AllThingsD conference, earlier this year.
The Guardian says the "watch" element of the name could relate to a TV-related product.
Analysts have expected Apple to make a move in the television space, but with margins on sets very thin and replacement cycles low - at about 10% per year - they have been unable to think of what it might do.
Benedict Evans of Enders Analysis has suggested that Apple could introduce an HDMI-powered dongle with the ability to use TV signals. But the company has given no indication of its intentions and there has been no industry chatter from TV content providers that would indicate a product is on the way.