Gasly has struggled since stepping up to a main Red Bull seat this season.
The Frenchman was promoted at the start of the campaign after Daniel Ricciardo left to join Renault.
However, Gasly is sixth in the Drivers’ Championship with 63 points, despite having the same car as Max Verstappen, who has 181 points.
It has led to team principal Christian Horner pulling the trigger during the summer break.
Thai-Brit driver Albon will swap places with Gasly for the remainder of the season.
“Alexander Albon is being promoted to the Team to drive alongside Max, while Pierre will return to the Red Bull sister team, Scuderia Toro Rosso,” a Red Bull statement read.
“Red Bull are in the unique position of having four talented Formula One drivers under contract who can be rotated between the Team and Toro Rosso.
“The Team will use the next nine races to evaluate Alex’s performance in order to make an informed decision as to who will drive alongside Max in 2020.
“Everyone at the Team looks forward to welcoming Alex and supporting him during the next phase of his F1 career.”
Gasly has come under fire at several times this campaign for his inability to challenge at the front of the grid.
It was thought Red Bull may drop the 23-year-old and replace him with Toro Rosso’s top performer Daniil Kvyat.
But Horner has instead offered Albon the chance to prove his credentials.
And the team boss knows it is tough for any drivers when they are racing against a team-mate of Verstappen’s calibre.
“I think it’s very tough,” he said last week.
“If you go up against Verstappen at the moment – for me arguably he is the most in-form driver on the grid – that’s an enormous barometer for any driver to go up and be measured against.
As a competitor, you always want to measure yourself against the best that you can.
“So, he’s a benchmark that obviously Pierre is measuring himself against.”