Anna Stern is a fictional character on FOX series The OC. She is played by Samaire Armstrong.

Spoiler warning: Plot or ending details follow.

Anna Stern met Seth Cohen early in Season One. Having just moved to Newport Beach from Pittsburg, she was paired with Seth's new friend Ryan Atwood to attend the annual cotillion. Seth and Anna connected instantly as they talked about their shared passion, comic books. When Ryan was unable to attend, Seth and Anna went to cotillion together. Seth turned down Summer Roberts, the love of his life, to go with Anna, which became somewhat of an omen of their relationship to come.

When Anna returned to school after a summer sailing trip, she and Seth picked up where they left off. Anna, realising how much Seth liked Summer, began to give him advice on how to attract her. It soon became apparent, however, that Anna liked Seth.

At the annual school carnival, Anna admitted, when asked by Ryan, that she did like Seth, but understood that he would never see her as anything more than a friend. When she kissed him later that night, Seth assumed that it was part of their plan to make Summer jealous and Anna didn't correct him.

Soon, though, Seth became aware of Anna feelings, at the same time Summer admitted that she had feelings for him. The previously girl-less Seth now had two amazing girls who liked him, and he had no idea what to do!

Things came to a head at Thanksgiving, when he invited Anna to his house. Summer turned up univited and he hid Summer in Ryan's pool house, then raced back to the house and he took Anna up to his room. Seth spent the afternoon racing between Anna and Summer, but before long, was caught out by the furious girls.

Anna and Summer formed an unlikely friendship for awhile after this, which was shattered when Seth delivered them a heartfelt apology. The two girls both did their best to try to win his affections. At Christmukkah, however, the girls forced him to choose between them before someone got hurt. Seth told both girls that he just wanted to be friends with them.

On New Years, Anna found herself lonely and morose at a fancy New Years party. She went to Seth's house, and the New Year saw the two of them making out on Seth's bed.

Their relationship had a rocky start, with both Anna and Seth afraid to tell Summer, whom they had both become friends with. When they did, she seemed fine with it, but it became apparent that she was determined to break them up.

While on holidays in Palm Springs, Anna and Seth seemed likely to sleep together. But a few 'innocent' comments from Summer about them being like brother and sister put a halt to that. Later on, their similiarities began to bother Seth.

Summer started hanging out with the couple, and Seth began paying her more attention. Anna realised that Seth was still in love with her, and broke up with him.

After a trip back to Pittsburg, Anna returned to find Seth and Summer were together. Although she remained friends with Seth, she missed Pittsburg too much, and decided to move back.