O My Father is a Latter-day Saint (LDS or Mormon) hymn written by Eliza R. Snow who felt inspired to write it after Joseph Smith, Jr. had taught her the principle of heavenly parents. Interesting in terms of Mormon theology in that it is the one of the few authoritative references to the "Heavenly Mother", who is assumed to exist but remains otherwise officially unacknowledged.

After discussing pre-mortal existence and a sense of belonging to "a more exalted sphere" in heaven, stanza three reasons that the if there is an eternal Father there must also be an eternal Mother:

I had learned to call thee Father, Through thy Spirit from on high,

But until the key of knowledge Was restored, I knew not why.

In the heavens are parents single? No, the thought makes reason stare!

Truth is reason, truth eternal Tells me I've a mother there.

The Times and Seasons first published the words 15 November 1845, more than a year after Joseph Smith, Jr. was killed. The poetry was later set to music and included in Latter-day Saint hymnals (including the current).

Though several Mormon denominations (among them, The Church of Jesus Christ of Latter-day Saints and The Fundamentalst LDS Church) accept the doctrine of a Heavenly Mother as true, all prohibit the offering of prayers to Her. In the early 1990's, The Church of Jesus Christ of Latter-day Saints excommunicated several female LDS shcolars for advocating prayers to a Heavenly Mother

The Reform Mormons are the only Mormon denomination who openly address Deity as "Heavenly Mother" or as "Heavenly Parents" (in addition to the traditional phrase "Heavenly Father."

Using the innovative theology of Mormonism's Nauvoo period (the period during which Snow wrote her hymn)as their foundation, Reform Mormons are unique among all Mormon denominations in that they incorporate the song's principles into their faith and practice.