A pretty blonde Catholic girl who works at The Cheesecake Factory with Penny (0309). She is studying microbiology (although she also considered both physics and ice dancing when she was choosing her career 0310) and is working as a waitress to put herself through school. Penny sets up a date between Bernadette and Howard, and the two of them eventually hit it off when they discover that they each have similar problems with their mothers (0305). After a bit of a shaky start (0309), the two start a relationship (0310). Howard then starts introducing her to everyone as "my girlfriend Bernadette". She finds his attentions charming. Bernadette doesn't understand most of Howard's humour, but she laughs anyway because she says it makes him "light up" when she does (0310).
Howard and Bernadette broke up in the spring of 2010. Howard didn't bother to mention this fact to anyone, including his best friend Raj, until several weeks later (0321). They broke up because Bernadette discovered Howard having virtual sex with a female troll character in the World of Warcraft online game (0404). In mid-October, 2010, Howard fesses up to what happened and asks Bernadette if they might be able to see each other again. She agrees and they have another date.
In episode 0413 Bernadette's last name "Rostenkowski" is revealed.
Bernadette is played by Melissa Rauch.