The Reds will travel to the AESSEAL New York Stadium to take on The Millers.
Paul Heckingbottom’s side will round off their pre-season campaign with an away tie at South Yorkshire rivals Rotherham United.
The Reds will make the short trip on Saturday 29th July for the 3pm kick-off.
Rotherham were relegated from the Sky Bet Championship last season and will now be attempting to win promotion at the first attempt upon their return to Sky Bet League One.
The two sides met twice last season with Barnsley running out comfortable winners on both occasions, with 4-0 and 0-1 score lines.
Ticket details will be confirmed in due course.
Please keep an eye on barnsleyfc.co.uk for anymore announcements regarding friendly fixtures.
Pre-season schedule so far:
Guiseley AFC (a)
Tuesday 11th July, 7.30pm
Grimsby Town (a)
Saturday 15th July, 3.00pm
Coventry City (h)
Tuesday 18th July, 7.45pm
Tuesday 25th July, 7.30pm
Rotherham United (a)
Saturday 29th July, 3pm.