A teacher who was trusted by a regional community in South Australia has been jailed for more than seven years over the abuse of three young girls.

Trent James Hay, 48, has been sentenced to seven years and six months after being found guilty of two counts of indecent assault and two counts of sexual abuse of a child.

WATCH ABOVE: Teacher sentenced over abuse of 3 young girls in South Australia.

Know the news with the 7NEWS app: Download today

Hay was teaching at a Whyalla primary school, about 385km from Adelaide, where he committed the offences on separate occasions.

Their victim impact statements, read out in court in May, said the girls now struggle to sleep and regularly cry about the abuse at the hands of Hay.

In the district court on Wednesday, Auxiliary Judge Barrett said, “Your offending was a breach of trust to the children, their parents and the school”.

Hay’s jail sentence was backdated to March 14.