The brief includes an ongoing media outreach campaign and stakeholder engagement programme.
The news comes as Addison Lee has been told to remove thousands of free cigarette bins from London streets, as Westminster Council said it wanted to prevent the area from being overrun with ‘excessive’ adverts.
Addison Lee is also awaiting the outcome of a judicial review into its attempt to make TfL let minicabs use bus lanes.
Ogilvy PR UK MD Michael Frohlich said: ‘Addison Lee is an iconic brand and part of the fabric of London. As a pioneer in innovative technology and an excellent service providers, Addison Lee is an exciting company to be working with.
‘We will be building on the fantastic reputation the firm has forged for itself over the years and help to translate that success at scale as the company continues to grow.’
Ogilvy PR is reporting to Addison Lee's marketing and PR manager Alistair Laycock.
Founded in 1975 by John Griffin, a former minicab driver, Addison Lee has grown from a single car to a fleet of 4,500 vehicles across London.
As London’s largest minicab company, Addison Lee now carries more than 10 million passengers a year and more than 50 per cent of FTSE 100 companies have a corporate account with the company.