Holders Leeds Rhinos will face St Helens at Warrington’s HJ Stadium in the first Challenge Cup final to be played on a Friday night.
Rhinos’ tie will be played on Friday, July 31 (8pm) and televised live on BBC 2.
It is the second successive year Rhinos have had an ‘away’ semi-final, after beating Warrington at St Helens in 2014.
Leeds are due to play host to Catalans Dragons in Super League on the Sunday before the semi-final, but chief executive Gary Hetherington indicated they will not bring that game forward to give them a longer turnaround.
Saints are at home to Hull KR on the Friday of the the week before the Cup tie.
Headingley has been selected as the venue for the other semi-final, between Hull KR and Warrington Wolves.
That will be played on Saturday, August 1 (12.45pm) and broadcast on BBC 1.
Ticket prices for both semi-finals start from £20 for adults and from £10 for concessions and go on sale at 9am on Friday.