Kristoffer Rein (18 February 1912 - 18 July 1993) was a Norwegian politician for the Christian Democratic Party.
He was elected to the Norwegian Parliament from Sør-Trøndelag in 1961, and was re-elected on two occasions. He had previously been a deputy representative from 1958 - 1961.
Rein was born in Stadsbygd and deputy mayor of Stadsbygd municipality during the term 1947 - 1951, and mayor in the periods 1955 - 1959 and 1959 - 1962.