The walkway will connect Bray Harbour to the Dun Laoghaire cycling network and provide an alternative scenic cycling route and walkway into Bray.
The opening of the new walkway comes after works took place to stop remnants from the old landfill being washed into the Irish Sea.
The €2 million coastal project began in 2021 after being delayed due to Covid restrictions.
Local authorities in the area stopped using the dump over 50 years ago.
However due to coastal erosion, more than more than 104,000 cubic metres of waste was washed into the water, causing serious environmental concerns.