Migrant associations in Calais organised the commemoration at the Richelieu Park, denouncing what they deemed "deadly" migration policies by governments.
"Is it enough to commemorate them? Of course not, we have to find solutions," Calais resident Maryvonne Lombard said during the homage.
France pledged on Thursday to step up surveillance of its northern shores, but migrants huddling in makeshift camps said neither that nor a tragic drowning the day before would stop them from trying to cross the Channel to Britain.
Seventeen men, seven women and three teenagers died on Wednesday when their dinghy deflated in the Channel, one of many such risky journeys attempted in small, overloaded boats by people fleeing poverty and war in Afghanistan, Iraq and beyond.
Wednesday's was the worst such incident on record in the waterway separating Britain and France, one of the world's busiest shipping lanes.