The storm, also known as Jangmi, brought heavy rains to the southern island of Mindanao island on Monday, where floods destroyed bridges and roads and forced thousands of residents to flee to evacuation centers.
By Tuesday it hit the country’s eastern and central islands, where most of the deaths occurred.
Blowing at gusts of up to 50 miles per hour (80 kilometers per hour), Seniang killed 12 people when a landslide buried two vans and six houses near a mountainside highway in eastern Catbalogan City, Mayor Stephanie Uy-Tan said.
She added that voices could still be heard from one of the vans and that rescue efforts were ongoing.
Olive Luces, a regional civil defense official, said 11 members of a family died after a house was washed away by flash floods in central Cebu province. Six other people were missing in the same town.
In eastern Leyte province's Tanauan town, devastated last year by Typhoon Yolanda, army rescuers retrieved five bodies from a house buried by a landslide.
A 65-year-old man drowned in southern Compostela Valley province while another resident remains missing after crossing a swollen river.
In central Bohol province, an 80-year-old man drowned and a 10-year-old girl died in a landslide that hit her home in southern Butuan City, officials said.
Earlier this month, Typhoon Hagupit affected more than 1 million Filipinos, causing at least 21 deaths. Last year Yolanda left more than 6,300 dead with a further 1,000 still missing. An average of 15 typhoons hit the Philippines every year.