He joins from Citroën, where he was head of product and brand strategy.
Prior to this, he worked at Vauxhall Motors for 16 years, where his roles included brand manager and group product manager.
Cullis is tasked with implementing a marketing strategy in line with Korean carmaker’s plans to double sales in the UK within five years.
“I have experience with volume manufacturers which I think will help the company achieve this by developing the brand and finding new ways to market the products,” said Cullis.
“The products are already impressive – the new Santa Fe, i30 and i10 for example are as competitive as anything Europe or Japan can offer in the class.
“The products we have coming into the market over the next few years are even more exciting.
“It is now up to us to let consumers know about them and create sustainable growth.
We will be investing heavily in media, PR and other brand-building activities to make sure everyone knows about Hyundai and understands the brand,” he added.
Cullis said he was excited to be in a job where he can change and shape the future strategy of a forward-moving company.
Predecessor Jim Campbell held the marketing role for six years.
He left in March and is now believed to be working on his private property portfolio.