The smaller format will run alongside the full-size September issue of Elle from 6 August and will contain the same editorial content and retain the usual £3 cover price.
Lara Wilkins, the publisher of Elle, said: "The launch of the travel-size edition is a response to the changing needs of the consumer. As has been reflected in the successful re-sizing of other premium publications, such as The Times and The Independent, readers are looking for greater choice."
The magazine is also set to undergo a major redesign following the hiring of the new art director, Marissa Bourke, from Conde Nast's Vogue earlier this week.
The shake-up of Elle also saw the appointment of Lorraine Candy as the editor in April. She joined from The National Magazine Company's Cosmopolitan.
Elle recorded a 201,309 July to December ABC circulation figure and trails in 13th place in the women's monthly magazine market.