The new born has been named Camden Jack Cutler and Cavallari personally confirmed the happy news on Twitter, reported Ace Showbiz.
"We are thrilled to welcome Camden Jack Cutler into the world. He was born this morning weighing 7 pounds. Everyone is doing great," Cavallari posted.
Camden is Cavallari's first child with the Chicago Bears quarterback, Cutler who she has been dating since 2010.
Cavallari and Cutler briefly broke their engagement in July last year before announcing that they were back on in November. The pregnancy was announced in January.
Cavallari hosted a baby shower in May in West Hollywood, with her former 'Hills' co-stars, Heidi Montag and Spencer Pratt and Stephanie Pratt, in attendance.