Jacob Dahl Jensen is the fourth child of Robert Jensen and Ulla Dahl. He was born 9 April 1999. He has older sister Anna Dahl-Vestergaard from 1995, younger sister Laura from 2000, older brothers Lasse from 1997 and Johan from 1998. He lives in Ballerup, Copenhagen, Denmark. He is the boyfriend of Sofie Enevoldsen.
In 2001, when he was 2, he started nursery at Børnehuset Ved Skoven, in Egebjerg, Ballerup, Copenhagen, Denmark.
In 2005, when he was 6, he started 0th grade at Egebjergskolen in Egebjerg, Ballerup, Copenhagen, Denmark.
In 2015, when he was 16, he started Niels Brock Gymnasium in Copenhagen, studying hhx with Danish, English Spanish, International Economics, and Marketing at level A.