Anglo-Welsh Cup: Ospreys in one-off St Helen's return
Ospreys will play at St Helen's for the first time since 2005 when they host Harlequins in the Anglo-Welsh Cup in November.
The Liberty Stadium-based team will also return to Bridgend's Brewery Field to face Bristol in January.
Ulster were the last top-flight rugby union visitors to Swansea RFC's St Helen's home, a Celtic Cup game Ospreys won 23-16.
Ospreys also have games in the Anglo-Welsh Cup at Cardiff Blues and Wasps.