The ad campaign, created by DDB London, uses the slogan "Smart but Casual" to target affluent weekday FT readers who are looking to unwind at the weekend.
The new-look magazine is positioning itself as having "style with substance". Changes include an expanded food and drink section, more space for the City's biggest characters, and better paper stock.
Pagination will increase from 48 pages to 56 pages as part of a concerted push by the publisher to encourage the FT's weekday readership to pick up the paper at the weekend.
The FT Weekend, available on newsstands on both Saturday and Sunday, is believed to be struggling to retain its readership, although official figures are not published.
Caroline Halliwell, director of brand and B2B Marketing at the FT, said: "The FT Weekend and its new look magazine is full of personality and our campaign reflects this. We’re looking to attract new readers, as well as regular FT weekday readers, who want a smart but casual read at the weekend when they are off duty."
In the launch issue, historian Simon Schama will profile prime minister David Cameron in the leader's first magazine interview since assuming power in May.
The profile is due to appear the day before the Tory Party Conference gets underway in Birmingham.
Print ads will run in current affairs weeklies The Economist, The Spectator and The Week, and consumer magazines Country Life, Decanter, Esquire, Tatler and GQ.
Media planning and buying has been handled by WPP agency Maxus.
Print activity will be supported with an online campaign featured on food and lifestyle websites such as MrandMrsSmith.com and Squaremeal.com.
The new campaign will also include digital escalator panels at London Underground stations every Friday evening in October, while Facebook advertising and polls will direct readers to the official Financial Times fan page.
Sales promotions will rollout from October to December and will include in-store posters and point of sale materials in 1,500 retailers across the UK.
The FT has also signed a month-long partnership with boutique cinema chain Curzon to promote the new-look supplement in its Mayfair, Chelsea, Soho, Bloomsbury and Richmond theatres.