The Commonwealth Bank said it would offer fee exemptions and an interest rate freeze, amongst other measures, to ensure viable farms and businesses survived the big dry.
It joined Westpac and the National Australia Bank which have drought assistance measures in place, while the ANZ said it would outline a relief package tomorrow.
Commonwealth Bank chief executive Ralph Norris said the bank acknowledged the nation's agriculture industry had experienced an "overall income downturn over a prolonged period".
And while there have been droughts in the past, he said "the current challenges are profound".
"We appreciate that our customers need our support at this time and, for that reason, we have a comprehensive special emergency assistance program to help farmers in drought-declared areas," Mr Norris said in a statement.