Conditional bail has been granted to a young Queensland man accused of a one-punch assault that left a NSW teenager in critical condition in hospital.

A man accused of a one-punch assault that left a teenager in critical condition in a NSW hospital has been granted bail.

Karl Sibley, 21, allegedly followed a 19-year-old out of a house party at Orange late on Saturday night and punched him in the side of the head.

On Tuesday Sibley appeared before Wellington Local Court charged with reckless grievous bodily harm.

Conditional bail was granted and he is due in Orange Local Court on February 13.

Police allege the teen Sibley struck was knocked unconscious and cracked his head on the road.

After the assault he was rushed to Orange Base Hospital with serious head injuries and later airlifted to Sydney’s Westmead Hospital for surgery.

Sibley, originally from Queensland, was arrested on Sunday afternoon at a house in Cumnock.