Five had earlier planned to launch its HD channel on Freeview but has now settled with Sky.
The development follows Ofcom's announcement that it had withdrawn the Freeview capacity from Five as it could not provide the regulator with a launch date for the channel.
Ofcom, which had reserved a date for Five's HD channel last June, said it would no longer hold the spot for the broadcaster because Five was unable to meet "certain key criteria by the end of 2009."
Five HD, which will broadcast shows including Neighbours, Home & Away and international cricket, will be available to the over two million customers who have a Sky+ HD set top box.
Five HD is the 42nd HD channel to launch on BSkyB.