The exciting news comes nearly a year after the couple married in secret on 24 June last year with her parents Earl and Valerie Washington as witnesses.
Kerry, who was previously engaged to actor David Moscow for four years until 2007, tends to be reticent about sharing details of her private life.
What has been evident in recent months is how happy the actress is. While the 37-year-old American beauty never walks the red carpet with her strapping 6ft 2in husband, the couple have been seen together at awards ceremony afterparties.
They were spotted giggling in the famous photobooth at Vanity Fair's Oscars party in March, while the handsome 32-year-old planted a loving kiss on his wife's cheek. Before that Kerry was seen proudly introducing her man to colleagues from her hit TV series at the Golden Globes.
It's not known how Kerry met Nnamdi but they share similar interests. Scandal follows her character Washington fixer, Olivia Pope as she extricates her powerful clients from their messes, while trying to sort out her own tempestuous love life.
Away from screens she is a member of V-Day, a global movement that raises awareness of violence against women and girls.
Nnamdi was born in the US to Nigerian parents of the Igbo tribe. His name, meaning 'my father lives', is traditionally given to a child who is thought to be the reincarnation of his grandfather.
Couple at DGA awards with Helen Mirren's husband director Taylor Hackford
He graduated in corporate finance from Berkeley University, California, before going on to have a successful American football career which is thought to have garnered him a fortune worth between $30 and 50 million.
The sports ace combined this with philanthropic activities, such as establishing a foundation to help orphans and widows' in Nigeria.
New dad Nnamdi retired from sport in 2013, but has said he is interested in a career in broadcasting or acting.
As well as being a sports commentator, he has appeared in a number of films including Will Ferrell comedy Funny or Die and Fire with Fire featuring Bruce Willis and Rosario Dawson.