Season Two of Blue Bloods premiered on September 23, 2011 and lasted 22 episodes.
- Tom Selleck as Francis "Frank" Reagan, Police Commissioner and widowed father.
- Donnie Wahlberg as Daniel "Danny" Reagan, Detective.
- Bridget Moynahan as Erin Reagan-Boyle, Assistant District Attorney and single mother.
- Will Estes as Jamison "Jamie" Reagan, rookie police officer and recent Harvard Law graduate.
- Len Cariou as Henry Reagan, retired Police Commissioner, father of Frank and grandfather of Danny, Erin and Jamie.
- Jennifer Esposito as Detective Jackie Curatola (episode 4-present), Danny's partner.
- Amy Carlson as Linda Reagan, wife of Danny.
- Sami Gayle as Nicole "Nicky" Reagan-Boyle, Erin's daughter.
- In Episode 1 "Mercy" the criminal is sent back to Croatia to a Judge and Noose, impling that he will be put to death. Croatia has not had a death penalty since 1990 and is now a member of the European Union which does not allow the death penalty.
|01||Mercy||September 23, 2011|
|Frank is put on the spot when a supporter for the mayor is found dead and the mayor wants Frank to position it as a random act of violence to the public. Meanwhile, Jamie goes on his first undercover assignment at a bar where he meets and bonds with a suspicious patron. Tony Bennett and Carrie Underwood make cameo appearances.|
|02||Friendly Fire||September 30, 2011|
|When Danny is put on modified assignment after an incident in which he shot an undercover cop who failed to identify himself, he faces Internal Affairs investigators who begin looking to his state of mind on that day.|
|03||Critical Condition||October 7, 2011|
|Three men attempt to rob a bank and Danny discovers that one of attempted robbers is a former cop. Also, Jamie works with Luisa Sosa, his new partner.|
|04||Innocence||October 14, 2011|
|Erin reopens an 18-year-old rape case, in which Frank was the arresting officer. Meanwhile, Danny and Jackie investigate the murder of three teenagers in a park, who seemed to have been killed for no reason.|
|05||A Night on the Town||October 21, 2011|
|Danny's and Linda's romantic getaway weekend is pre-empted by a fatal auto accident and medicaid fraud case. Working undercover as "Jimmy Reardon," Jamie continues his assignment as he renews his acquaintance with the mercurial nephew of a high-profile mob boss.|
|06||Black and Blue||November 4, 2011|
|Frank deals with a political crisis after Jamie and Renzulli enter a black religious center in response to a 911 call and are injured by the church's security team who prohibits them from entering. Frank and Donnie must prevent a race riot by a charismatic black community leader.|
|07||Lonely Hearts Club||November 11, 2011|
|Jackie goes undercover as an escort when she and Danny track down a serial killer who is murdering prostitutes in hotel rooms. Meanwhile, Erin meets a potential suitor at an art gallery who shares her interests.|
|08||Thanksgiving||November 18, 2011|
|Henry's heart attack on Thanksgiving eve leaves the family worrying about him. While Danny and Jackie look into a suicide that may not be what it seems, Frank and the mayor disagree about a threat to the city.|
|09||Moonlighting||December 2, 2011|
|Danny accompanies a dangerous ex-mobster who is helping him find bodies on cold cases. Meanwhile, Jamie works undercover in a boiler room operation in order to dig up secrets on the Sanfino crime family.|
|10||Whistle Blower||January 6, 2012|
|When Erin's confidential informant is murdered, she blames herself and works to help Danny discover who killed him.|
|11||The Uniform||January 13, 2012|
|Danny and Jackie investigate a murder scene at a diner, where a witness claims a uniformed officer fled the scene after shots were fired. Jamie has to take a second job to help pay off his Harvard Law School loans.|
|12||The Job||February 3, 2012|
|While driving home from a family dinner with Linda and his children, Danny's car strikes a man who had run into the road ahead of him. As Danny attends to the wounded person, another man who was chasing shoots at Danny, and the bullet just misses the children in the truck. As Danny and Jackie try to locate the shooter, a shaken Linda proclaims she is tired of being "second fiddle" to the NYPD. Meanwhile, Frank deals with survivor's guilt when he learns that his old partner is dying from a 9/11-related disease.|
|13||Leap of Faith||February 10, 2012|
|When a rich woman dies of a heart attack, her eccentric daughter claims that she received a message from God, who told her that her stepfather (guest star Timothy Busfield) is the murderer of the woman.|
|14||Parenthood||February 17, 2012|
|When a man's family is robbed and beaten in front of him, and the assailant is shot and killed, the Reagans debate about how far they would go to protect their family.|
|15||The Life We Chose||February 24, 2012|
|When a close friend to the Reagan family, an undercover detective, is killed in the line of duty, Linda begins to worry about Danny as his relentless search for the killer starts to take a toll on his emotional state.|
|16||Women With Guns||March 2, 2012|
|A high-profile reporter and close friend to Frank is nearly assaulted while she is out with him, and Danny and Jackie search for the would-be attacker. Meanwhile, Jamie's undercover case investigating the Sanfino crime family comes to a critical stage.|
|17||Reagan v. Reagan||March 9, 2012|
|As Erin prosecutes a woman accused of killing her husband, the defendant's attorney is murdered and Danny is assigned to the investigation. When Danny is put on the stand to be questioned, things get heated between the brother and sister.|
|18||No Questions Asked||March 30, 2012|
|Danny is put in a difficult position when a gun linked to a robbery is brought in to the NYPD's gun buyback program. He must decide to either arrest the suspect or follow the "no questions asked" rule.|
|19||Some Kind of Hero||April 6, 2012|
|Danny causes waves in the department when he investigates a closed case, the suicide of a firefighter, at the insistence of the man's 11-year-old son. Meanwhile, Jamie saves a baby from a burning building, but worries it will jeopardize his undercover work if he is billed a hero in the press.|
|20||Working Girls||April 27, 2012|
|Danny and Jackie are assigned to protect a key witness in a Russian mob trial, but when an attempt is made on her life, they realize there is a leak on the task force. Meanwhile, Erin is offered a job as deputy mayor, which would have her working directly with her father.|
|21||Collateral Damage||May 4, 2012|
|Danny and Jackie investigate the suspicious murder of a high rolling investor, who had injuries from a fight, but no marks on his hands. Meanwhile, Frank puts Jamie under house arrest, after hearing the Sanfino family has put out a hit on "Jimmy Reardon".|
|22||Mother's Day||May 11, 2012|
|Frank must race to stop a biological weapon attack on New York City, while keeping it a secret from his family during their most sentimental holiday, Mother's Day. Meanwhile, a long-standing conflict between Danny and Jamie comes to a head.|