John Underwood is the son of Ricky Underwood and Amy Juergens. He is also the paternal biological grandson of Bob and Nora Underwood, paternal adoptive grandson of Sanjay and Margaret Shakur, and maternal grandson of George and Anne Juergens, as well the nephew of Ashley Juergens, who named him, and Robert Scott Johnson. He is portrayed by Matthew and Joseph Levinson.
He was conceived on a couch in the summer of 2008 after his mother and father had a one-night stand at band camp. There was a lot of drama concerning him.
Amy wasn't sure whether to keep him, or give him up for adoption, but when she is about eight months pregnant, she decides to keep John after she gets convinced by Grace Bowman and many of her other friends to keep him and later got much support from her peers.
At one point, Ricky's biological father, Bob Underwood asked Ricky to illegally sell John before he was born, for $100,000. Jack Pappas later witnessed Bob buying drugs. With the help of Adrian and her father, Ruben, they were able to put Bob back in jail for a parole violation.
John was born two weeks early. According to The Secret Diary of Ashley Juergens, he was born on February 6, 2009. During the school day, he stays at the church daycare where his mother works after school hours.
In the series finale, Amy leaves to go to New York for college, leaving John and Ricky to live in the apartment above the butcher shop. She states she loves Ricky, but is not in love with him, and agrees to remain friends to raise John.
However, the show's creator said that after Amy went to New York, she realized her love for Ricky and not Ben. Ricky and John then moved to New York to be a family with Amy.