Chef-patron Garvey said the Covent Garden restaurant would be known as Encant (meaning 'charm' or 'spell' in Catalan) from 1 November with a second site in Central London to launch under the same name in early 2017.
He said: "When I opened Duende in March this year, I could never have hoped or imagined that within our first year we’d be in a position to even think about opening a second site, let alone actually do it.
"I didn’t really think through finding a name that could grow with us, in terms of trademarks and licensing, so now that we’re expanding it feels like we’ve got a golden opportunity to get it right this time."
Garvey said the Maiden Lane restaurant, his first solo venture, would change in name only and continue to serve Spanish-style tapas dishes from an open kitchen.
“Encant has similar connotations to duende – which is literally an imp or sprite but can also mean magic or charm, the same as encant," he said. "The new name won’t change the spirit of the restaurant one bit, in fact it really embraces what we want the feeling of our enlarged business to be now and in the future."
The new Encant, which is due to open in London's W1, will have a similar menu to the original Maiden Lane site, but with an additional focus on Catalan cuisine.
Garvey, who grew up in Barcelona, worked at a number of restaurants in Spain before coming to London to open Bravas Tapas with Bal Thind at St Katharine's Docks.