Joseph P. Bencomo was born on March 23, 1931 in Pinos Altos, New Mexico United States to Anastacio Bencomo and Rita Bencomo, and had siblings Bernarda Bencomo Martinez, Robert Bencomo, Domingo Bencomo, and Antonio Bencomo. He married Dora Bencomo in 1951, and they were married until Joseph's death on December 28, 2022. Joseph Bencomo had children Christina Bencomo, Joseph Bencomo, David R. Bencomo, and Peggy Bencomo.