The launch of the W04 is taking place at the Spanish track the day before it hosts the first of the pre-season tests.
There will be huge interest in Mercedes' new car this season following the arrival of Lewis Hamilton to replace Michael Schumacher.
Mercedes took its first win in last year's Chinese Grand Prix, but subsequently tumbled down the order.
Shanghai victor Nico Rosberg stays on to partner Hamilton.
Toro Rosso will launch its 2013 car on the same day: the STR8 will be unveiled at Jerez the day before the first winter test, and just a few hours after Mercedes unveils its new car.
Red Bull's junior squad faltered in 2012, falling one place to ninth in the constructors' championship.
It has retained drivers Daniel Ricciardo and Jean-Eric Vergne, but shaken up its technical department.
Ex-Sauber man James Key arrived during 2012 and AUTOSPORT has learned that Steve Nielsen is joining Toro Rosso from Caterham.