McLennan starts at the London listings and entertainment weekly in December.
He will edit the Consume section, replacing Rachel Phillips who left last month to join Emap Elan women's glossy Elle (PRWeek, 6 September).
McLennan has been at ES for a year, before which he was at Elle himself for five years, most recently as commissioning editor.
He is currently discussing changes to the Consume pages with Time Out editor Laura Lee Davies, but refused to comment on his ideas: 'It is confidential. We are still having chats about it,' he said.
Consume is one of Time Out's largest sections, comprising shops, interiors, style, health, gadgets and people. The section is currently overseen by acting editor Sarah Halliwell. Acting assistant editor is Stephanie King. McLennan's resignation comes as ES, the Friday magazine of the Standard, is relaunched under new editor Catherine Ostler. She aims to make it 'less bitty' and 'more focused'. The Standard's entertainment guide, Hot Tickets, has been renamed MetroLife and also relaunched.
