Loeb, Mikko Hirvonen, Jari-Matti Latvala, brothers Petter and Henning Solberg and Matthew Wilson will sign autographs from 12 midday in the city's Pitt Street Mall, near the corner of Market Street.
And joining them will be Wallabies squad member James O'Connor, helping to celebrate the start of two major international events on the following weekend, the FIA World Rally Championship on the Coffs Coast and the Rugby World Cup in Auckland.
The drivers are on their way to contest Rally Australia, round 10 of the 2011 WRC on 8-11 September.
Citroen driver Sebastien Loeb has his sights set on a record eighth straight world championship and is leading the drivers' standings as he readies his Australian assault.
Norwegian Petter Solberg, the 2003 world champion, also will represent Citroen at the Sydney autograph signing, while older brother Henning plus Hirvonen, Latvala and Wilson will represent Ford.
Sunday's autograph signing will be the drivers' only appearance in Australia outside the Coffs Coast rally and an event not to be missed by rally fans.