The Canadian former model will appear in two episodes of the sitcom, TVLine reports.
Simmons will play Brandi, a sports reporter who is hired to work alongside Robin (Cobie Smulders).
The 29-year-old's past credits include such films as 2007's Good Luck Chuck and 2010's Tucker & Dale vs Evil. Her previous television work includes roles on ABC Family's Kyle XY and The CW's The L.A. Complex.
She has also been cast in forthcoming NBC drama Hannibal - Bryan Fuller's take on Thomas Harris novel Red Dragon and the character of cannibal killer Hannibal Lecter.
How I Met Your Mother continues on Monday nights on CBS. In the UK, the series airs on E4.
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Watch a clip from How I Met Your Mother below: