The British motorist, who is racing in Super Formula this season, will push the 2nd day of the Sakhir test a week.
He will take over the RB15 from from regular race motorist Max Verstappen, who will push Tuesday.
The RedBull junior motorist had appointed a contemporary RedBull test as among his main targets for 2019.
He had been initially slated to operate a vehicle for that team last year but didn’t have the superlicence points required for the essential testing permit.
However, his Euro F3 championship bid faded and that end his hopes of securing the essential superlicence points.
Ticktum was a formal RedBull junior since 20 17, when he came back from a racing ban he chose up in late-2015 to get a high-profile episode below the security car in an MSA Formula race at Silverstone.
He is a two-time winner of the Macau Grand Prix, having obtained victory in the Formula 3 show piece event for the last couple of years.