Roger Peralta is Jake Peralta's father. He walked out on the family when Jake was seven, and has since reappeared infrequently in Jake's life. In some appearances he has chopped off his thumb.
Throughout the Series
Jake's mainly absentee father, Roger (guest star Bradley Whitford), comes to town to spend some time with his son. Jake can't wait to see him, but Charles is sceptical of Roger's intentions.
In Karen Peralta, Roger arrives as the surprise guest at Karen Peralta's house for Jake's birthday. Karen announces then that Roger and her are seeing each other again. Jake tries to break them up but later sees that Roger genuinely cares about Karen and agrees to let them be together.
In Two Turkeys, Jake's parents and Amy's parents are meeting one another for the first time. Upon Victor and Camila Santiago arriving for Thanksgiving dinner, Roger is half-naked from the bottom down since he couldn't decide which pair of pants to wear. He is not self-conscious of how he appears as he asks how their trip was flying in. The conversations between the parents are off to a rough start before the Thanksgiving meal so Jake & Amy bring out the alcohol and get them drunk. Roger begins competing with Victor over showing their support toward Jake & Amy's relationship. The two fathers' competition in topping the other get greater when each carving a turkey, to the point where Roger ends up cutting off his thumb accidentally.
Jake rushes his dad to the hospital, where Roger reveals to Jake that he has three half-sisters. After his left thumb is reattached to his hand, Roger reveals to Jake that he has half-brothers too.
In Jake & Amy, after the bomb scare caused the wedding to be cancelled, Jake mentions to Amy that their parents ended up having dinner together, that it sounded like they had fun and their dads only got into one arms-wrestling match. Amy asks who won and Jake tells her that neither because they both threw out their shoulders.
In Admiral Peralta, he meets up with Jake to talk about Jake's baby. Jake wants Roger to meet his father, Walter Peralta, and reconcile. Roger didn't want to see his father again. He goes to Jake's apartment and sees his father, who he insults about being a terrible father. After starting to bond, however, Walter throws Roger a can of beer and Roger misses, with the gender-reveal cake on the floor. After a disastrous clean job blindfolded since Jake didn't want to know the baby's gender, they call in Charles to help after they find out anyway to help clean up. However, during the restoration Roger puts Green Dye into the cake and later at the party accidentally cuts off his thumb which prompts Walter to walk out on him again. He tells Jake that he will be a great father since he already cares so much about this baby before he's even born.
Roger is shown to be untrustworthy, and often uncaring towards other people's feelings, such as cheating on his partners and not being considerate about Jake. However, Karen claims that he does have a more sensitive side, as he cared for her and brought her soup when she was sick.
Jake is shown to be very distrustful of his father, and he is unwilling to accept his father back into his life after numerous betrayals. Jake tells Charles that it's not blood that matters, as Roger has never been there for him, and he doesn't view Roger as his father figure, instead seeking a father figure in Holt.
Roger and Karen broke up because he left them, and also due to the numerous times he cheated, including with her best friend. Despite this, Karen is willing to look past it, and the two start dating again later in life. Karen tells Jake that Roger really cares about her now, such as when he flew in on his day off and brought her soup when she had bronchitis.
Not much is known about their relationship, other than the fact that he only visited her about 9 times throughout her childhood, one time sending his co-pilot, Steve, who taught her how to shave.
- He coached Jake's little league baseball team.
- Flies internationally from Albany to Quebec for Tribute Airlines.
- In Hostage Situation, he appeared as a potential sperm donor for Charles and Genevieve.
- He said he’s had sex with about 400 women.
- Was caught making out with a female clown in a bounce house on Jake's sixth birthday. 
- Learned Spanish from one of his mistresses. 
- He went to a single parent-teacher-conference, at which he had sex with the teacher on top of Jake's diorama.
- Once hooked up with the entirety of Kate's mother's book club.
- He fathered children, Jake's half-siblings, in all the hubs of cities with international airports --Atlanta, Newark, Dallas–Fort Worth, etc.
- Pretended to like golf to get away with cheating on Karen.
- Used to fly with Sully Sullenberger.
- Accidentally had both thumbs cut off and reattached.