The Romans will focus on 'bringing to life the brand’s mission to improve children's lives through developing healthy relationships with food'. The account was previously held by Mischief.
The remit includes creative campaigns, consumer media relations, content creation, experiential and influencer management.
"The Romans lived up to our expectations and delivered a pitch bursting with creative ideas that will allow us to demonstrate the value of our brand and develop a deeper emotional relationship with our customers – both new recruits and existing parents," Ella’s Kitchen marketing director Kim Gelling said.
"Their ideas were grounded in a smart strategy that will allow us to deliver coverage and conversation outside of our traditional heartland media, in order to ensure we maintain our position as the UK’s number-one baby food brand."
Roxy Kalha, a director at The Romans, described the Ella’s Kitchen story as "rich, authentic and impressive". She added: "They have single-handedly reinvented their category and we are thrilled to be joining them in the next stage of their comms journey.
"The brief provides a great opportunity to differentiate Ella’s Kitchen from the ever-expanding competition, through campaigns that creatively explore the feeding moments that all parents experience and linking it to what’s being talked about, shared, sung about and watched in popular culture."
Ella’s Kitchen joins a growing roster of clients at The Romans, including Twitter, Ben and Jerry’s, PlayStation, Virgin Trains and Method.
The agency has been nominated for seven PRWeek UK Awards, including Best Small Agency, and was the only UK PR agency to win a D&AD Pencil at this year’s awards for its @JohnLewis Ad campaign with Twitter.
Recently, The Romans co-founder and CEO Misha Dhanak left the business.