The workers died at Ao Yon on a heavily sloping site where a new resort is being built.
Fellow workers were crying over their deaths as the young women's bodies were laid out and covered with sheets.
Killed were Nu, 25, Mo, 19, and May, 18. Other workers said the wall collapse came at the site of the Crystal Wild Resort, which is due to open later this year.
The resort is on a hill near the Khao Kad viewpoint lookout between Cape Panwa and Chalong. A fourth worker was injured and taken to hospital.
Authorities have just issued a major alert for potential land slips and floods, but the deaths today were unconnected with the severe weather forecast for the next few days.