Main •
Angie Harmon as Jane Clementine Rizzoli, a
Boston detective in the Homicide Unit. From an
Italian American family, Jane is brash, sarcastic, and often prickly but also a confident and independent woman as well as a brilliant detective. In the final season, Jane takes a new job as an instructor at the
FBI Academy in
Quantico, Virginia. •
Sasha Alexander as Dr. Maura Dorothea Isles, the Commonwealth of Massachusetts' Chief Medical Examiner. Isles is a forensic expert working at the Boston Police Department and Jane's best friend. Maura is socially awkward and cannot lie; if she does, she breaks out in hives. •
Lorraine Bracco as Angela Rizzoli: Jane, Frankie, and Tommy's overbearing and fiercely protective mother. •
Bruce McGill as Vincent "Vince" Walter Korsak, Rizzoli's former partner who is promoted to sergeant-detective in season two. •
Lee Thompson Young as Barold "Barry" Frost (seasons 1–4): Rizzoli's second partner. While adept with computers and technology, he is terrified of dead bodies and becomes ill at the sight of blood. In the season five premiere, Barry was killed in a car accident due to Young's death in 2013. •
Jordan Bridges as Francesco "Frankie" Rizzoli, Jr.: a police officer and Jane's protective younger brother. He looks up to Jane, but does not like feeling caught in her shadow as he tries to make his own way in the police force. In season four, Frankie is promoted to detective and begins taking night classes in computer science to increase his skill set in season five. In season seven, he begins a romantic relationship with Nina and eventually successfully proposes to her. •
Brian Goodman as Sean Cavanaugh (seasons 3–4; recurring, seasons 1–2, 5): the lieutenant of the Boston PD's Homicide Unit. Fiercely loyal to Jane and an old friend of Korsak, Sean is willing to bend the rules from time to time. •
Idara Victor as Nina Holiday (seasons 6–7; recurring, season 5): a crime scene analyst and computer technician. Formerly a detective in Chicago, Holiday transferred to Boston Homicide to hone her analytical skills in an office-based environment. She begins a romantic relationship with Frankie Rizzoli in the seventh season, and the two become engaged in the series finale. •
Adam Sinclair as Dr. Kent Drake (season 7; recurring, season 6): a lab technician, and Maura's new assistant starting in the sixth season. He is a
Scot with a military background, having served in the Middle East. In the series finale, "Ocean-Frank", Kent is set to oversee the Commonwealth of Massachusetts' Medical Examiner's Office during Maura's sabbatical.
Recurring •
Annabeth Gish as Alice Sands, a former police academy classmate of Jane's who dropped out and turned to a life of crime after Jane usurped her position as top of the class. •
Tina Huang as Susie Chang, the senior criminalist of the Boston Police Department's crime laboratory. She has described herself as having a very physical memory. For example, when circumstances required her to take point in an investigation, she made various dioramas to explain her reasoning. In the third-season episode "Class Action Satisfaction", she is revealed to be a nudist. She is killed in the sixth-season episode, "Misconduct," as part of a complex plan to frame the forensics department for poor handling of a recent case, but the subsequent investigation exposed the killer's true agenda. •
Donnie Wahlberg as Lieutenant Joe Grant, an old rival of Jane's since childhood. He constantly made fun of her, calling her "Frog Face" and "Roly-Poly Rizzoli" because she was slightly chubby when she was younger. When he leaves for Washington, D.C. after being appointed as the liaison between Boston and Homeland Security, he claims that he has liked her for a very long time. •
John Doman as Patrick "Paddy" Doyle, an Irish-American
crime boss and the biological father and protector of Maura Isles. To protect her from his diehard father, Paddy claimed Maura had died as a baby and made sure she was adopted. •
Jacqueline Bisset as Constance Isles, a visual artist and the adoptive mother of Dr. Maura Isles. She loves Maura but is sorry that they don't have a close relationship. •
Colin Egglesfield as Thomas "Tommy" Rizzoli, the well-meaning, good-looking but dim younger brother of Jane and Frankie. Convicted for running over a priest (non-fatally) in a crosswalk on his third DUI violation, he returns to the family fold following his release from prison. As of the season two episode
"He Ain't Heavy, He's My Brother", he is 32 years old. He tries to kiss Maura to pay her back for her kindness, but she stops him and he develops a crush on her as he works on starting a new life. He later fathers a son, T.J., and grows up a lot. •
Chris Vance as Charles (Casey) Jones, an old flame of Jane's from high school, reunited with Jane during season two. A
US Army officer assigned to the Middle East, he returns to Boston in season three but breaks up with Jane because of injuries that left him partially paralyzed below the waist. He returns in season four's first episode after a successful operation and proposes to Jane, but when he receives the offer of a promotion to colonel, he decides to stay in the army, leaving Jane behind. • Darryl Alan Reed as Rondo, a man with access to information in the criminal world who becomes a
confidential informant to Jane •
Billy Burke as Gabriel Dean, an FBI agent often seen working with the Boston Homicide detectives and the Medical Examiner's Office. He later becomes romantically involved with Jane, but she ends this relationship when he tries to use her as part of a plan to capture Paddy Doyle, which forced Jane to shoot Paddy. •
Chazz Palminteri as Francesco "Frank" Rizzoli Sr., father of Jane, Frankie, and Tommy. He owns and runs a plumbing business called Rizzoli and Sons. He and Angela separate and then divorce after the first season. He later tries to have their marriage annulled so that he can remarry in a Catholic ceremony. He returns to announce he has stage 2 prostate cancer; despite the news, his family finds overlooking his past transgressions difficult. •
Matthew Del Negro as Giovanni Gilberti, a dimwitted former classmate of Jane's, now an auto mechanic. •
Michael Massee as Charles Hoyt, a sadistic serial killer who kidnapped and stabbed Jane in both hands and continues to threaten her, even from behind bars. Hoyt appears in several episodes, including "See One, Do One, Teach One" (episode 1), "I'm Your Boogie Man", and "Remember Me". •
Sharon Lawrence as Dr. Hope Martin, Maura's biological mother, who was told by Paddy Doyle that Maura died as a baby. She is a noted medical doctor with another, much-younger daughter, Cailin. •
Emilee Wallace as Cailin Martin, Hope's daughter and Maura's half-sister. Despite Caitlin's initial hostility, Maura later donated her kidney to Cailin to save her life. •
Alexandra Holden as Lydia Sparks, a ditzy young woman who is heavily pregnant when Angela befriends her. It is soon revealed that her child's father is either Angela's son Tommy or Angela's ex-husband Frank. Eventually a test confirms that Tommy is the father, and the boy is known as T.J. for "Tommy Junior." •
Jaz Sinclair as Tasha Williams (season 5), a high-school student who witnessed a shooting and was saved from the shooter by Jane. ==Production==