Mather Zickel (born c. 1970) is an American actor, mainly known for comedy roles, as well as the character Kieran in Rachel Getting Married. A native of New York City, he has worked in both film and television since the late 1990s. He graduated from the Pomfret School in 1988 and New York University in 1992. He co-starred as "Rob the Federal Agent" in season two of Delocated and as Will Keen in the ABC sitcom Man Up!.