Wiktionary
oh my goodness
interj. (alternative form of my goodness English)
Wikipedia
Oh My Goodness
"Oh My Goodness" is a song by English singer-songwriter Olly Murs, from his second studio album, In Case You Didn't Know (2011). Written by Murs, Adam Argyle and Martin Brammer, it was released as the album's third and final single on 1 April 2012 and became Murs's sixth UK top-20 hit, reaching a peak of number 13.
Usage examples of "oh my goodness".
And oh my goodness, who should be with Mam'zelle, studying a big French chart, but the Head, Miss Theobald herself!