He has been named ad director on the title, which is Wallpaper founder Tyler Brule's first publishing venture since founding the company. Ellis has also worked in a similar capacity on The Times and The Sunday Times.
Monocle, set for an international launch in February, will cover current affairs, business analysis, travel, culture, design and fashion.
The magazine is pitched as a cross between Vanity Fair, The New Yorker and weekly news magazines and is aimed at affluent, well-travelled readers aged 25 to 55.
It will be edited by Andrew Tuck, currently executive features editor of The Independent on Sunday, with Brule as editor-in-chief.
Pamela Mullinger, former head of fashion advertising on Wallpaper and currently Winkreative's business development director, will be the magazine's publisher.
Winkreative will also launch a website, www.monoclemagazine.com.