Manganiello was born in Pittsburgh, Pennsylvania. His parents Charles and Susan were both born in Boston, Massachusetts but moved to Pittsburgh a few years before Joe was born. He has one brother, Nicholas who works behind the scenes in the entertainment industry in Los Angeles. Joe graduated from the suburban Mt. Lebanon High School in 1995, where he was a letterman in football, basketball, and volleyball. He appeared in a senior high school production of Oklahoma! as "Jud Fry" and was very involved with the high school's TV studio where he would write, direct, edit and act in movies with all of his friends. He is a graduate of the Carnegie Mellon School of Drama, a prestigious school in Pittsburgh.

Manganiello's first job out of drama school was appearing opposite Tobey Maguire, Kirsten Dunst, and James Franco as “Peter Parker’s” nemesis, “Flash Thompson” in Spider-Man (film) directed by: Sam Raimi. He reprised his role several years later making a brief cameo at the end of Spider-Man 3. He played Sophia Bush’s love interest, “Owen Morello” on seasons five, six, and seven of The CW’s drama One Tree Hill (TV series) and played Jason Segel's buddy "Brad" on several seasons of the CBS comedy How I Met Your Mother. Manganiello could also be seen as "Stu" on FOX’s half-hour comedy, ‘TIL DEATH, opposite Brad Garrett and Joely Fisher and as Linda Cardellini's love interest, “Officer Litchman” on E.R. (NBC) for several seasons. Other credits include: The starring role of “Lt. Sean Macklin” in FOX’s Behind Enemy Lines: Colombia which co-starred former WWE Superstar Mr. Kennedy and a recurring role as Tori Spelling's boyfriend on So Notorious.

Manganiello will play the role of werewolf Alcide Herveaux opposite Anna Paquin in the third season of HBO's True Blood, based on The Southern Vampire Mysteries by: Charlaine Harris.
 

Manganiello holds a BFA in Acting from the Carnegie Mellon School of Drama where he studied all styles of classical theatre. In June of 2009 he starred on stage as “Leo Belraggio” alongside Doris Roberts, Richard Thomas, Harriet Harris, and Maria Dizzia in the West Coast Premiere of Terrence McNally’s, UNUSUAL ACTS OF DEVOTION, directed by: Trip Cullman, at the La Jolla Playhouse in San Diego. Other notable theatre roles include: Stanley Kowalski in A Streetcar Named Desire for the West Virginia Public Theatre and starring roles in the premieres of Gloria Calderon Kellett's Wounded (which is now a short film), and The Chick Magnet for which he was an HBO Aspen Comedy Festival Finalist.