“If we want to be successful then we have to employ the best people and for me, Steve is the best,” said Southgate.
Holland has worked as Southgate’s assistant since 2013 – first with England Under-21s and more recently with the senior squad, following Sam Allardyce’s departure as boss in September.
“We have worked very closely for three years and I have upmost respect for the way that he works, his professionalism and the detail of his preparation,” added Southgate, who was made permanent England manager in November.
“I’d like to thank Chelsea for allowing Steve to join up with us over the last three years.
“It’s great that Steve is able to work with us on the March camp but getting him on a full-time basis is very important and I was more than prepared to wait until May for that to happen.”
Holland, who managed Crewe from 2007 to 2008, joined Chelsea in 2011. He was part of the Blues’ backroom team for their Champions League and FA Cup double in 2012, the Europa League win in 2013 and the Premier League and League Cupdouble in 2015.