The Ugly Betty star will join the cast of the CBS comedy as a potential love interest for Barney Stinson (Neil Patrick Harris), according to TV Line.
Newton will play a character called Quinn, and will appear throughout much of the current seventh season, with her first episode slated for January.
The most recent episode saw Barney end his relationship with Nora (Nazanin Boniadi), only to be rejected by Robin (Cobie Smulders).
Becki Newton most recently starred in the NBC series Love Bites, which was cancelled after one season.
> How I Met Your Mother: Six seasons in 60 seconds - video