Arnold Pieter Bernard "Arno" den Hartog (born 8 November 1954 in Oss) is a former field hockey player from the Netherlands.
He was a member of the Dutch National Team that finished sixth in the 1984 Summer Olympics in Los Angeles.
Den Hartog earned a total number of 109 caps, scoring seventeen goals, in the years 1979-1985.
After his hockey career he started working for the Royal Dutch Field Hockey Federation.