Kerry Blackman faced a trial in the Bundaberg District Court.
He was found guilty of four charges of sexual assault dating back to 2017.
Blackman will face a sentencing hearing next week.
Former Gidarjil Development Corporation chief executive Kerry Blackman has been convicted of sexual assault against a young woman almost a decade ago.
Blackman faced a two-day trial in the Bundaberg District Court this week.
He pleaded not guilty to four charges of sexual assault and one charge of common assault relating to a woman between 2017 and 2023.
Crown prosecutor Kate Thamm told the court Blackman had a "sexual interest" in the then 23-year-old woman, and the charges stemmed from a series of interactions between them.
In one incident in 2017, Blackman confronted the woman outside a toilet and whispered in her ear and bit it, before grabbing her backside.
"She could smell the soap on him," she said.
"The force of how he touched her moved her underwear."
Ms Thamm said Blackman bought the woman lingerie as a gift and sent her an inappropriate text message.
"When a man buys lingerie and tells her she has a tight bottom, it only means one thing," Ms Thamm said.
"He is sending her text messages about her tight arse, he had a sexual interest in her and he acted on it."
Blackman's defence barrister, Simon Lewis, told the jury the text could be categorised as "outdated male banter" rather than a sexual advance.
In another interaction, Blackman grabbed the woman around the head with his hands and kissed her on the lips.
The court was closed to the public during the witness's testimony but was reopened for the closing statements of the prosecution and defence.
During the closing statements, Mr Lewis questioned the timeline of dates and events that were reported to police and the clothing the woman was wearing during one of the alleged incidents.
"The account has moved, the year has moved," he said.
"Two of the five charges she never [previously] reported to police."
The jury requested clarification on whether the woman was wearing shorts, slacks, or trousers during one of the alleged sexual assaults.
"That remains unanswered," Mr Lewis said.
In his summary, Judge John Allen KC told jurors they were to consider whether the woman was a witness and if they were convinced beyond a reasonable doubt that the sexual assaults and common assault occurred.
After five hours of deliberations, the jury of six men and six women returned their guilty verdict for four charges of sexual assault.
He was found not guilty for a single charge of common assault.
Judge Allen revoked Blackman's bail. He was remanded in custody, with a sentencing hearing listed for next week.