Unemployed dance teacher Leonard Watters, 25, claimed the judge on Britain's The X Factor had groped him at Krystle nightclub in Dublin, Ireland in April, 2011.
The TV star vehemently denied the allegations and Watters was subsequently found to have lied to authorities investigating the case.
He pleaded guilty to charges of making false reports to police and was ordered to serve time behind bars.
Watters appealed the punishment, but his plea was denied on Friday (06Jul12) and Judge Katherine Delahunt increased his sentence to 11 months. The last five months will be suspended on the condition that he cooperates with probation officials and enrols in an alcohol rehabilitation programme.