Alex N. Niño was born in Tarnac, The Philippines, and dreamed of being a comic artist since he was a small boy. He began his career assisting his father, who was a photographer. He was a medical student at the University of Manilla, but eventually chose an artistic profession. In 1965, after learning the finer points of the comics profession from Jess Jodloman, he started a collaboration with Clodualdo del Mundo and created 'Kilabot Ng Persia' ('The Terror of Persia') for Pilipino Komiks. Later, he teamed up with Marcelo B. Isidro to create 'Dinoceras'.
By 1975, Niño ended his collaboration with Gomez and started to focus on the U.S. market, like many of his contemporaries. Already active in the US since the early 1970s, he contributed to D.C. mystery titles and drew comic adaptations of literary classics.
He continued his adaptation work at Marvel in 1975, and also drew for the company's 'Unknown Worlds of Science Fiction'. Starting in 1977, he was additionally present in Warren's horror magazines, Eerie, Creepy and Vampirella. He was active as an illustrator for Heavy Metal and Byron Press. During the 1980s, Niño's work appeared in Batman Annual and Space Clusters, as well as publications by New Comics Group and Pacific Comics. In 1994, he returned to the comics field more prominently with a new version of 'Conan the Barbarian', scripted by Roy Thomas.