Ellie Kemper has scored an invite to Robin and Barney's wedding.

The former Office secretary will guest star on at least one episode of How I Met Your Mother Season 9, TV Line confirms, stopping by the CBS sitcom as Cassie.

The character is described by co-creators Carter Bays and Craig Thomas as attractive, single and, as Ted will apparently discover, "unfortunate" guests at this fall's nuptials, around which the entire final HIMYM season will be based.

Earlier this week it was also confirmed that Sherri Shepherd would play a role on Season 9, coming on board as a plane passenger who tussles with Marshall.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.