This is an overview of the regular, recurring, and other characters of the CBS TV crime drama franchise Blue Bloods with the original series (2010–24) and its spinoff Boston Blue (starting in 2025).

Reagan family Family tree

Frank Reagan

Commissioner Francis Xavier Reagan, portrayed by former Magnum, P.I. star Tom Selleck, is the patriarch of the Reagan family.

Frank is the younger son of Henry (Len Cariou) and Betty Reagan, born in Bay Ridge, Brooklyn, New York in the early 1950s. His older brother Peter Christopher Reagan died of leukemia at the age of 18 months, over a year before Frank was born. Frank married Mary Margaret Reagan (née Conor) in the early 1970s, and they had four children together: Joe, Danny, Erin and Jamie. Frank is also a loving grandfather to Erin's daughter Nicky Reagan-Boyle (Sami Gayle) and Danny's two children, Jack (Tony Terraciano) and Sean Reagan (Andrew Terraciano). In Season 10's "Family Secrets" Frank learns that he also has one more grandson, Joseph Hill, the son of Paula Hill, whom Joe Reagan had met at the academy. Paula said the two had had a brief affair and that she never told Joe about her pregnancy or his son. Paula visits Frank and reveals the news in an effort to get her son, a young detective in the firearms unit, assigned to a less dangerous precinct.

After serving in the United States Marine Corps during the Vietnam War during which time he held the rank of Lieutenant and was awarded the Navy & Marine Corps Achievement Medal, Frank became the third generation of Reagans to become a police officer. He began his career as a patrolman and was later promoted to Detective 3rd Grade. He thereafter served in various positions across the city, including Chief of the Brooklyn South Division and the Chief of Department of the NYPD, culminating in his appointment as Police Commissioner.

On September 11, 2001, Frank was working in the North Tower when the South Tower collapsed. He spent days at Ground Zero and took refuge at St. Paul's Chapel, where he and other officers slept in the pews. Frank was appointed the Police Commissioner by Mayor Frank Russo (Bruce Altman). In 2011, after the election of Carter Poole (David Ramsey), Frank offers to tender his resignation, but Poole decides to keep Frank on as PC. In the first season, Frank is well regarded and respected by his officers and his city, to the point where the mayor felt threatened by his popularity; however, by season 6, public opinion regarding the police – and him personally – has changed so drastically that he gets booed off-stage while speaking at Columbia University. However, in season 7, new mayor Margaret Dutton affirms that his polls are better than any of the New York City mayors.

Danny Reagan

Detective First Grade Daniel Fitzgerald Reagan is the eldest surviving son of Commissioner Frank Reagan. He is portrayed by New Kids on the Block singer Donnie Wahlberg.

On the job for 15 years (as of season 1), Danny took a leave of absence from the New York City Police Department to serve two tours in the Iraq War as a Marine. He had enlisted and served in the Marines shortly after high school and prior to joining the NYPD and either stayed in the Marine Corps Reserve and was activated or volunteered to reenlist at the start of the war. Danny saw combat in Fallujah and was the only member of his platoon to come home alive (resulting in some post-traumatic stress). During his time in the Marines, Danny was decorated for heroism.

Danny has a traditional police outlook; his hotheadedness and harsh methods of detective work sometimes get him in trouble, which his father worries about. When asked if his son "crosses the line" and violates procedure from time to time, Frank answered, "I think he walks on the line". Danny is hard on other policemen and detectives when he feels they are unprofessional or not doing their duty to its utmost. He is currently assigned to the Detective Squad of the 54th Precinct and partnered with Detective Maria Baez. In "Most Wanted", the audience learns that he leads the Manhattan South Detective Borough in both collars and complaints. In "Love Stories", Baez and Danny are awarded the NYPD Medal for Valor for their actions in "Partners".

As a detective with the NYPD, Danny carries a Kahr K9 in 9×19mm as his duty weapon and drives a Dodge Charger on duty, which replaced his previous Chevrolet Impala 9C1. He also owns a Glock 19 in 9×19mm and previously used a Smith & Wesson 5906 in 9×19mm. Danny drove a Jeep XJ Cherokee as his personal and family vehicle from Season 1 to Season 5, while Linda drove a rather troublesome 2001 Kia Sedona/Carnival; this vehicle was replaced when Henry lost his driver's license and gave Linda his car. In Season 6, Danny's Cherokee was replaced by a fourth-generation Ford Explorer.

Erin Reagan

Assistant District Attorney Erin Reagan is Frank Reagan's only daughter. She is portrayed by Bridget Moynahan. A New York County Assistant District Attorney and single mother, Erin is the second child and only daughter of Frank Reagan and his late wife Mary. She grew up in Bay Ridge, Brooklyn, with three brothers, Danny, Joe, and Jamie. She may have been somewhat wild when growing up. In season 5, the audience learns that she graduated top of her class from Columbia University. Erin later attended Fordham University School of Law. In season 6, Erin celebrated her 40th birthday.

Erin is divorced from John "Jack" Boyle (Peter Hermann), a criminal defense attorney whom she met when they were 19. Daughter Nicky is the couple's only child. In "Old Wounds", Erin finally changes her surname from Erin Reagan-Boyle back to Erin Reagan. Since her divorce, Erin has had a few romantic interests. She and her boss, District Attorney Charles Rosselini (Bobby Cannavale), flirted with each other and even shared a kiss after a date, but nothing ever came of it mainly due to Erin's reluctance about dating her boss. In 2011, she met Jacob Krystal (Fred Weller) at an art gallery; she later learned that he was an art thief who returned once-stolen works to their rightful owners, and he left town. In 2013, after being shot in a courtroom hostage situation, Erin began dating her ex-husband Jack, but eventually broke up with him when she realized Jack only wanted to date and that he did not want a serious commitment. In 2014, Erin met defense attorney Robert McCoy on a speed-date, and the two became romantically involved until he was appointed interim District Attorney, at which point she said that she could not be romantically involved with her boss.

Erin is almost raped and killed in "Re-Do", though Frank saves her life by shooting her attacker dead. In "To Protect and Serve", Erin is taken hostage and shot in the arm at the courthouse. She is saved by Danny when he shoots her assailant.

In "Working Girls", Erin is offered the position of Deputy Mayor of Operations by Mayor Poole, but she turns him down. In "Ends and Means", Erin is promoted from Senior Counsel to Deputy Bureau Chief of the Trial Bureau. In the season four finale, she filed a complaint against her boss, Bureau Chief Amanda Harris, upon learning she had abused her power. In season six, Erin was considered for a judgeship. Erin is on the short list to become District Attorney in the season 11 episode "In the Name of the Father", after her boss, DA Samar Chatwell, is arrested on corruption charges. While Erin is on the short list to be named Acting DA by the governor, the governor ultimately chooses the then-Acting DA for Fulton County, Georgia (Atlanta) for the job.

Like the rest of her family, Erin is licensed to carry a firearm. Her weapon of choice is the Glock 19 in 9×19mm, and according to Frank, she is a better shot than Danny and Jamie. In season 8, the audience learns that Erin had wanted to join the police force like her the rest of her family but chose law and became a prosecutor instead.

Jamie Reagan

Sergeant Jameson Reagan is the youngest son of Frank Reagan. He is portrayed by Will Estes. First introduced as newly graduated cadet and former Harvard Law School graduate, Jamie is the youngest child of Frank Reagan and his Mary. Jamie grew up in Bay Ridge, Brooklyn with two older brothers, Danny and Joe, and an older sister, Erin. His shield number as a patrol officer was 60528 and as a sergeant is 71181.

Henry Reagan Henry "Pop" Reagan is a former New York City Police Commissioner and the father of current Commissioner Frank Reagan. He is portrayed by Len Cariou. He is described in one source as "grizzled family patriarch Henry Reagan, a retired NYPD police commissioner who saw military action in World War II and Korea".Roger Sabin, Ronald Wilson, Linda Speidel, Cop Shows: A Critical History of Police Dramas on Television (2015), p. 187.

The retired New York City Police Commissioner and father of Frank, being the only one who calls him by his full name Francis. In the season 13 episode, "Homefront", broadcast in 2022, Frank states that Henry is 88 years old, which would place his year of birth around 1934. Henry's childhood was hard due to his father, Charles, an Irish immigrant, World War I veteran and former police officer, being an alcoholic and unable to hold a job. Henry was a Marine in World War II (though this is inconsistent with his later-stated age) and Korea and joined the NYPD in 1952. He got married in 1955. Like his grandson Danny, Henry is socially conservative and hates the political correctness of modern law and order. His wife of 46 years Betty died December 2, 2001. It is later revealed that Henry and Betty had another son, Peter Christopher, who died of leukemia at the age of 18 months, over a year before Frank was born.

Henry once rode with one of the first female patrol officers, Colleen McGuire (Anita Gillette). Henry admitted that they both had romantic feelings for each other, but they never acted on them since he was married. He had his boss reassign Colleen to a different partner to avoid putting his marriage at further risk but remained good friends with her. In "Stomping Grounds", Henry mentions that during his days as a Detective with the Vice Squad he transferred out of the unit when he started to see every woman on the street as a prostitute. In "Town Without Pity", Henry mentions that during the New York City blackout of 1977 he was stationed in the South Bronx. Actor Len Cariou, who portrays Henry, is separated in age from Tom Selleck by only six years and wears make-up and a dental prosthetic to appear older.

Linda Reagan Nurse Linda Rose Reagan (née O'Shea) was Danny Reagan's wife. She was portrayed by Daytime Emmy–nominated actress Amy Carlson.

The wife of Danny from 1996 to 2017 and mother of their two sons, she loves her husband and the Reagan family, but at times, Danny's obsessive attitude toward collaring criminals makes her wonder whether he views his job as a higher priority than his family. In seasons one and two, Linda is a stay-at-home mother, but she returns to her nursing job at St. Victor's Medical Center in season three.

Linda has an older sister Wendy (Laurie Williams) and a niece, Sofie, who is a fashion model. She also has a brother Jimmy O'Shea (Kevin Dillon), who has been in and out of trouble with the law.

In "New Rules", Linda is shot at the hospital by a teenage gangster who had been ordered to kill a witness, but she eventually makes a full recovery. In "Under the Gun," Linda is mugged while working a community health van in the projects and uses her father-in-law's influence to bypass the New York City pistol permitting process to obtain an unrestricted concealed carry permit and buys a .38 Special Smith & Wesson Model 36 revolver. Ultimately Linda decides that she does not want to be armed after all and gives the pistol to Danny.Reale, Willie; and Wade, Kevin. Blue Bloods, Episode 5/09, "Under the Gun". First aired December 12, 2014. Retrieved May 18, 2017.