The 'Need You Now' hitmaker welcomed a daughter with husband Chris Tyrrell on Monday (22.07.13), and the couple have named the newborn Eisele Kaye.
Hillary announced the news on her Twitter page by writing: ''She's here, and we are in HEAVEN!!! Eisele Kaye, our beautiful angel, HAPPY BIRTHDAY!!! (sic)''
The 27-year-old country star announced her pregnancy in December and discovered she was expecting a daughter in March.
She wrote in December: ''Chris & I are excited to announce that our Christmas gift has arrived a little early this year!#We are having a BABY! We feel so blessed!!! (sic)''
Hillary wed Chris - who is a drummer for Lady Antebellum - in January 2012 after dating for just over two years.
The couple first got together in July 2010 and Chris joined Lady Antebellum's full-time band in October 2011.
A message on the official Lady Antebellum Twitter page reads: ''Congratulations to @HillaryScottLA and Chris, parents of the beautiful Eisele Kaye! Happy birthday and we love you!! (sic)''