Exit question: What on earth religion forbids inter-racial marriage again?
Christian Identity
Nation of Islam and similar racist black power sects, including racist "black Israelite" cults
Racist Asatru/Odinism/Wotanism (David Lane used WOTAN as an acronym for "Will Of The Aryan Nation") and other racist European revival movements (especially in Russia)
Esoteric/occult Nazism
Ariosophy
neo-Nazi Satanism
Cosmotheism (William Pierce's made up religion)
Creativity (formally World Church of the Creator)
Kinism (another white supremacist cult; popular with paleocons)
Old-school Southern Baptists
Mormon fundies
Far-right Hindus
Far-right Jews (like Kahanists)
That Urantia Book also support racism and eugenics.
There's also racist Muslims (they tend to hate blacks and Jews), and, if I recall correctly, there are religious arguments they use for it.
There's a bunch of other racist whackjob cults within neopaganism, occultism, New Age, etc. But you get the picture.