A number of events will be held in the capital to commemorate the day.
In a ceremony being held by trade union UCATT at Tower Hill, 69 black balloons will be released – one for every construction worker killed in 2007/8.
On average, at least 10 workers are killed in London each year alone.
UCATT London regional secretary Jerry Swain, who will be speaking at the memorial, said more needed to be done to stamp out unsafe practices in the industry.
He said: "Workers are being killed on construction sites week in and week out. Most of these deaths were preventable.
"It is time that rogue construction bosses who don’t care about health and safety were brought to justice."
UCATT is campaigning for the government and Health and Safety Executive to increase the number of front-line inspectors in the construction sector and also introduce a zero-tolerance approach to health and safety breaches.
International Workers’ Memorial Day originated in Canada and has been held every year since 1989.