Clifford-Jones joins was previously European general manager for Intext and video advertising leader Vibrant Media in the UK.
He will be responsible for the development of LinkedIn's media sales channel across Europe, as well as building relationships with agencies, clients and third parties to develop and maximise the social networking site's ad revenue.
The appointment reflects an increase in European members of the site, with over one million members in the UK and more than five million in Europe, making LinkedIn the largest professional network.
Kevin Eyres, European managing director at LinkedIn, said: "We want to ensure that LinkedIn remains the professional network of choice in Europe and focusing on media sales is an important part of this. Henry's years of experience in managing and leading rapid growth digital advertising businesses is invaluable to our ambitious growth plans."