Andrew Chan, 31, married his Indonesian girlfriend Febyanti Herewila in a ceremony on Nusakambangan Island, home to several high-security prisons, his brother Michael said.
He could be put to death by firing squad as soon as tomorrow, along with seven other foreign drug convicts, after authorities at the weekend gave then formal notice of their executions.
"We've had a special day today," Michael Chan said as he announced the marriage after returning from a visit to Nusakambangan. "We've celebrated with some family and close friends.
"It's in the president's hands."
More From This Section
Chan met his future wife several years ago when Herewila, a pastor, began helping inmates in the jail where the Australian was imprisoned.
Chan and fellow Australian Myuran Sukumaran, both among the group facing imminent execution, are ringleaders of the so-called "Bali Nine" heroin-smuggling gang and were sentenced to death in 2006.
Australia has mounted a diplomatic campaign to save the pair but President Joko Widodo has vowed there will be no clemency for drug traffickers on death row in Indonesia.