Ricky Underwood - a drummer in the Grant High School band. His father sexually abused him when he was young, and as a result he is a foster child and also goes to therapy. In the episode Falling in Love it is revealed that Amy lost her virginity to Ricky and he is the father of her baby. Ricky is known as the school bad boy whose only truly serious relationship to date has been with Adrian Lee. Ricky and Adrian are FWBs (Friends with Benefits). Amy and Ricky are now living together while, Ricky is in his freshmen year in college and Amy is in her senior year in High School. Ricky and Amy are now engaged and pretending to be married.
Bob Underwood (Bryan Callen) - Ricky's biological father, who sexually abused him as a child and was addicted to drugs and alcohol. When he got out of prison on parole, he broke the restraining order that was supposed to keep him from Ricky, tried to get Ricky to sell him his unborn son, and bought drugs which ultimately sent him back to prison. He is a bad man.
Nora Underwood - Ricky's biological mother, who was turned and became addicted to drugs and alcohol as an escape to her husband's physical abuse of her and her son. Is released from prison as is now dating Ollie, who happens to be a woman. Nora now works for Bens father.
Margaret Shakur (L. Scott Caldwell) - Ricky's foster mother, who he considers both as his real mother and John's grandmother.
Sanjay Shakur - Ricky's foster father, who he considers both his real father and John's grandfather.
John Juergens (Joseph and Matthew Levinson) - Amy and Ricky's son. Was named by Ashley. And was conceived at Band Camp, on a couch.
Ethan (Michael Grant) - Ricky's younger foster brother who was kicked out of the Shakurs' house for stealing and selling those stolen goods. He was later allowed to come back.
Amy Juergens (Shailene Woodley) - Amy's first time making love was with Ricky Underwood at Band Camp. The 15 year old teenage mother of John Juergens. Dates and almost marries Ben Boykewich for a little while, but later on gets back with Ricky.
George Juergens (Mark Derwin) - Anne Juergens's ex husband, Amy and Ashley's father, Robbie's legal father, John's maternal grandfather and Moose's owner. George was once married to Kathleen Bowman. George is the owner of a furniture store.
Anne Juergens (Molly Ringwald) - George's ex wife, Amy, Ashley, and Robbie's mother, John's maternal grandmother, Mismy and Robert's daughter and Eugene's step-daughter. Anne is now a lesbian.
Ashley Juergens (India Eisley) - the younger daughter of George and Anne Juergens, the sister of Amy Juergens and aunt of John Juergens. Ashely went to culinary school in Italy.
Mimsy (Alice Hirson) - Anne's mother and Amy, Ashley, and Robie's grandmother.
Robert Scott - Anne's father and Amy, Ashley, and Robbie's grandfather. Robbie was named after him, but he's never appeared in the series and is implied to be deceased.
Eugene - Mimsy's second husband, Anne's step-father, and Amy, Ashley, and Robbie's step-grandfather.
John Juergens (Joseph and Matthew Levinson) - Amy and Ricky's son. Was named by Ashley. He was conceived at Band Camp, on a couch.
Robie Juergens(Logan and Cian McGrath) - Anne and David Johnson's son, George's legal son, Amy and Ashley's maternal half-brother and John's maternal uncle. Delivered by George; named after Anne's father.
Kathleen Tsegay (Josie Bissett) - previous wife of Marshall Bowman, mother of Grace Bowman, adoptive mother of Tom, and current wife to Jeff Tsegay. She was once married to George Juergens, who she married young just so she could have sex with him, but the marriage ended when she cheated on him.
Tom Bowman (Luke Zimmerman) - oldest child of Marshall and Katleen Bowman and older brother of Grace Bowman. He has down syndrome. He was adopted after his biological mother died and his biological father couldn't handle him. Many times throughout the show it is hinted that he has anger issues. He is now working at human resources at a company.
Jacob Bowman Gudina (Jordan Fisher) - Grace's half-brother, the son of Marshall Bowman and a woman he had an affair with while in Africa.
Ben Boykewich (Kenny Baumann) - Leo Boykewich's son, who joins the school band to meet Amy and falls in love with her, baby and all. He also has a baby girl(Mercy) who was stillborn, by Adrian his wife. Ben is a stud.
Leo Boykewich (Steve Schirripa) - Ben's father, a successful sausage salesman nicknamed the "Sausage King."
Sarah Helen Boykewich - Ben's mother; deceased. Her name was revealed in "Absent," when Ben visited the cemetery on the fifth anniversary of her death. She was born in 1963 and died in 2003.she had a drinking problem.
Camille Boykewich (Tricia O'Kelley) - Leo's third wife and Ben's new step-mother. She worked as Leo's personal assistant for years, eventually left the company because she couldn't stand that Leo hadn't been able to return her feelings and instead married Betty, and eventually married him after he divorced Betty.
Mercy Boykewich - Ben's daughter who was born a stillborn. Her mother was Adrian Lee. She was conceived in Ben's car in front of Amy's house.
Chloe Boykewich (Natalie Dreyfuss) - Leo and Camille's adoptive teenager daughter and Ben's adoptive sister. She was a victim of human trafficking until Jack helped her escape. She was the reason Leo and Camille moved up their wedding date.
Adrian Lee- daughter of Cindy Lee and Ruben Enriquez and the ex-wife of Ben Boykewich. She was a majorette at Grant High School with great grades, but a reputation for being promiscuous. She stopped being a majorette when she got pregnant, but lost her daughter to stillbirth. She's now attending the local college.
Cindy Lee (Paola Turbay) - Adrian's mother who is a flight attendent. Was dating George Juergens and is now married to Ruben.
Ruben Enriquez (Philip Anthony-Rodriguez) - Adrian's father. Now married to Cindy.
Mercy Boykewich - Adrian's daughter who was born a stillborn. Her father was Ben Boykewich. She was conceived in Ben's car in front of Amy's house.
Unnamed - Ruben's second child and Adrian's half-brother. Ruben got married and started a family when Adrian was six-months-old. The marriage didn't last and he now lives with his mother in Mexico. He has never been introduced in the show, but his existence has been mentioned on three separate occasions.