Olivia Baker is the mother of the late Hannah Baker and the wife of Andy Baker. She is portrayed by Kate Walsh.
She is first introduced along with her husband, Andy. They arrived at Liberty High School to pick up the rest of their daughter's belongings, in hope of finding something to help them win the lawsuit against the school.
She finds some incriminating evidence that could solidify their lawsuit: the "hot list" Alex made. However, Andy isn't sure that this will help them. Olivia doesn't care as she needs to find a reason that explains why her daughter killed herself.
Olivia arrives once again at Liberty High and goes to the principal and asks if he noticed anything different about Hannah, how she acted in school. Since she's brought a lawsuit against the school, the principal can't lawfully talk to her. Olivia goes into the girl's bathroom and finds graffiti about Hannah. Not only about Hannah, but the entire wall of the bathroom is covered with insulting comments about other girls. She comes to the conclusion that Hannah was being bullied and that's all the evidence she needs.
She catches Clay Jensen as the culprit for toilet papering her house, but it turned out that he was just trying to help. When she learns that he was an old friend and co-worker to Hannah, she invites her into the house. Olivia tries to pressure him into helping them find out why Hannah killed herself. When the Baker's store is losing customers, Olivia is sure it's because of Hannah, and people are scared of them.
While out to dinner, they talk to a woman about Hannah as if she is still alive. She tells the mother that Hannah is 17, is going to start applying for colleges soon, that time flies. Her mother tells her father that it is nice to sometimes not be the mother of the dead girl. He suggests moving, but Olivia doesn't think it would help.
Olivia finds the list with all the names of the people on the tapes, although she doesn't know what the list means.