Last winter, Poya Asbaghi, 36, left the Swedish U21 national team and took over Barnsley.
The move was a failure.
On Friday they fell against Huddersfield and then it was clear that the club will leave the Championship.
Now Barnsley announce that Asbaghi is leaving.
- It has been a great privilege to work and I wish everyone the best for the coming seasons, he says.
Assistant coach Ferran Sibila, with a past in Gothenburg and Sundsvall, is also leaving.
Barnsley played 26 games under Asbaghi's rule.
There were four wins, seven crosses and 15 losses.