The ceremony was held June 3 at Playwrights Horizons.
Smith, a two-time Tony Award nominee for The Grapes of Wrath and Buried Child, and Kilgore co-founded the Susan Smith Blackburn Prize for women writers.
The other award recipients were Jessica Hecht, Paula Vogel, Laura Marks, Tanya Barfield, Jill Du Boff, Lear deBessonet, Julie Crosby and Denise Scott Brown.
Jiehae Park was recognized with the Leah Ryan Prize for Emerging Women Writers.
The Lilly Awards were founded by Julia Jordan, Marsha Norman and Theresa Rebeck and are named for Lillian Hellman, a pioneering American playwright who famously said, "You need to write like the devil and act like one when necessary."
More information can be found at thelillyawards.org.
