There was no incumbent digital agency for the volunteer-led organisation, which was founded in 1863.
Zone has been tasked with reviewing the charity’s digital strategy and finding new ways that it can connect with audiences online.
The British Red Cross appointed Arthur London to create TV ads in 2014 after a review in 2013, having previously worked with Leagas Delaney.
Rosie Slater, the chief information officer at the British Red Cross, said: "We have a huge range of UK services which have already been made more efficient and effective through the adoption of digital.
"Our strategy now needs to reflect the scale of our service and ensure people in crisis are at its very heart."