The 36-year-old Oscar winner and mother of three will receive the organization's Grace Kelly Award at its Celebration of Babies event Friday at the Beverly Hills Hotel. The award recognizes celebrity parents committed to healthy pregnancies and families.
Witherspoon gave birth in September to a son, Tennessee, with her husband, talent agent Jim Toth. She's also mom to Ava, 13, and Deacon, 8, from her previous marriage to actor Ryan Phillippe.
"I was very lucky to have a healthy delivery and leave the hospital with a healthy full term infant, but so many families in this country do not get that experience," she said, adding that she hopes her involvement with March of Dimes calls attention to its efforts to prevent birth defects, premature birth and infant mortality.
Hollywood has a long history with March of Dimes, said event chair and Universal Pictures President Jimmy Horowitz. The tradition continues with this seventh annual celebrity luncheon, where star parents Susan and Robert Downey Jr., Brooke Shields and Chris Henchy, Elizabeth Banks and Max Handelman, and Mariah Carey and Nick Cannon are also expected. Cannon will serve as master of ceremonies for the private event.
The March of Dimes is also inducting new celebrity parents into its Stork Club. Members include Amanda Anka and Jason Bateman, Drew Barrymore and Will Koppelman, and Megan Fox and Brian Austin Green.