Albertalli was born and raised in the Atlanta metropolitan area, with her sister Caroline and brother Sam; where she still lives with her husband Brian, and two sons, Owen and Henry.[3] Albertalli attended Wesleyan University and majored in psychology, before moving to Washington, D.C. and earning her Doctor of Psychology degree from George Washington University.[2][4] She worked as a psychologist until 2012—when her first son was born—and subsequently decided to try writing a novel.[5] Albertalli was raised in a Reform Jewish household.[6] Albertalli cites Australian author Jaclyn Moriarty as her primary inspiration in becoming a novelist.[7] In August 2020, Albertalli came out as bisexual in an essay responding to people who had criticized her for writing about gay characters as a presumed heterosexual.