The track was written in 2016 during a songwriting retreat in Puerto Vallarta, Mexico, by Young alongside Trent Tomlinson , Tyler Reeve, and Kyle Schlienger.

: The idea came from a story Tomlinson told about his childhood. Every time he left the house, his mother would stop him and say, "Trent, in case you didn't know, I love you".

: The goal was to write a "simple and basic" love story that anyone could apply to their own relationship. Critical Success & Achievements In Case You Didn't Know by Brett Young (Single, Soft Rock)

: Young and his co-writers adapted the sentiment to a romantic context, focusing on how often people (specifically men) forget to verbalize their deep affection for their partners.

In Case You Didn't Know, a Single by Brett Young. Released 9 January 2017 on Republic Nashville (catalog no. n/a; Digital File). Rate Your Music Brett Young – In Case You Didn't Know Lyrics - Genius