Following their promotion last season, the Millers will welcome the Swans to the AESSEAL New York Stadium on Saturday July 30.
In other key dates, Paul Warne’s side make the short trip to Bramall Lane to face Sheffield United on Saturday September 10, while the Blades come to the NYS on Saturday February 4.
The break for the World Cup comes in November, with the Millers traveling to face Luton Town on November 12 before things kick off again on December 10 with a home match against Bristol City.
Rotherham are at home on Boxing Day with Stoke City the visitors. Millwall away is the New Year’s Day date, with Huddersfield at home sandwiched between.
The last five matches of the season will see the Millers play Luton Town (H) on April 15 followed by Burnley (H), Bristol City (A), Middbesbrough (H) and finishing up with Wigan Athletic away.