The deal, which is Casio's first TV sponsorship, was negotiated between ITV Commercial, 'The Only Way is Essex' production company Lime Pictures, and media agency Vizeum on behalf of Casio Sheen.
It includes a multi-platform sponsorship and licensing package as well as the show's second ever product placement agreement, following last season's deal with Ministry of Sound for its Marbella Sessions album.
Models from the Casio Sheen female watch collection due to feature in the show include the SHE-3504D-7AUDR, SHE-3503D-8AER, and SHE-4509SG-4AER.
The sponsorship package will run across broadcast, mobile and online platforms, with Sassy Films creating the idents.
The licensing elements will be activated off-air and include an opportunity to win a styling session at Minnie's Boutique shop (which is co-owned by Sam and Billie Faiers and appears in the series). The competition will run in-store at H Samuel, in the upcoming H Samuel catalogue, as well as through Casio Sheen's online channels.
According to figures from ITV, the ninth series of 'The Only Way is Essex' recorded an average consolidated audience of 1.4 million viewers and a 7% share of the audience.
Tim Gould, head of marketing at Casio Sheen, said: "We are really excited about this opportunity to partner with 'The Only Way is Essex'. We have some great new timepieces which we can't wait to show consumers, and with such high viewing figures this is a natural choice for our female collection."
Previous sponsors of 'The Only Way is Essex' include Blue Inc, the high-street fashion retailer, and the Unilever-owned laundry brand Surf.