The expensive delicacy is popular in many Asian cultures but some restaurants in Australia have already dropped it from the menu.
The Australian Marine Conservation Society and Greenpeace are among those who have teamed up for the Fin Free Cities campaign.
The manager at SEA LIFE Conservation Fund, Claudette Rechtorik, says Australia was actively involved in the shark-fin trade.
"We do export a significant amount of shark fin, we also import shark fin, we import it from New Zealand and they still take part in live finning," she said.
But the practice of "live finning", the cause of many shark deaths around the world, is illegal in Australia.
"In Australia we have a policy where we actually have to land the entire shark carcass, so [that means] the fin attached to the body," Ms Rechtorik said.
Some US states have banned the trade and possession of shark fin and the alliance wants to build support for a similar ban in Australia.
