Erin Jessica Cahill (born January 4, 1980) is an American actress. She is best known for her roles as Jen Scotts in Power Rangers Time Force,[1] Ted Mosby's sister, Heather, in How I Met Your Mother, and Kendra Burke in Saving Grace. She had a recurring role as Felicity in the ABC series Red Widow. She is also noted to be the first lead female character for the Call of Duty franchise, as Chloe 'Karma' Lynch in Call of Duty: Black Ops II.

Passionate about charity, Cahill co-founded the group, Charitable Living, which services the local community throughout the year with various fundraisers and days of volunteering.

In May 2015, Cahill joined non-profit group BuildOn and traveled to Malawi to promote education and build schools.