David Rees took paid leave from his Conwy council job while sitting at Llandudno Magistrates' Court - but kept money paid out for lost salary.
Rees, 65, of Llandudno, was convicted of six counts of fraud.
On Thursday, he was given a 16-month prison sentence, suspended for two years, at Warrington Crown Court.
Richard Riley, of Mersey-Cheshire Crown Prosecution Service, said Rees's reputation was "now in tatters".
The court heard Rees - a superintendent registrar who had sat as a magistrate since 1995 - claimed a financial loss allowance (FLA) for time he spent in court.
On his claim form he wrote: "I am paid by my employer whilst sitting in court but am required to claim as close to this as possible and pass refund to them."
In a later claim he said: "Whilst sitting in court I am paid by my employers but pay back the amount claimed as FLA when applicable."
But when the claims were investigated, the court service found a discrepancy between the amount claimed by Rees and the sums paid back to the council, with thousands "unaccounted for".
The total shortfall was £9,839, but in an annual declaration, Rees said all of it was due to be paid back to the council.
His 16-month sentence was suspended for two years after the court heard he was a carer for his mother, who is blind and in poor health.
He must also complete 280 hours' unpaid work and pay £3,000 in prosecution costs.
Senior crown prosecutor, Mr Riley said: "A formerly public-spirited man who volunteered to help with the justice system has now been given a suspended jail term himself and he has only himself to blame."
A Conwy magistrate who fraudulently claimed £10,000 in lost wages for time he spent in court has been ordered to repay the money.