Osman (pictured) left her role with the Royal Family last year, having joined in January 2014 following just over half a year as comms secretary to Prince Charles and the Duchess of Cornwall.
A former journalist, Osman joined the Royals from a role in corporate comms at Sony Europe, having previously worked for Sky, Channel 5 and the BBC.
At the latter, where she held the top comms job from 1999 to 2007, Osman was in the hot seat during the furore around its reporting of the so-called ‘sexed-up’ Iraq dossier and oversaw the resignations of chairman Gavyn Davies and director general Greg Dyke.
On her departure from Buckingham Palace last year, the Queen awarded Osman with the Insignia of a Lieutenant of the Royal Victorian Order, the highest order given for personal services to the monarch.
Osman joins the likes of former US senator George Mitchell, former UK Conservative Party leader Lord Hague, and ex-Downing Street comms director Sir Craig Oliver as a senior advisor at Teneo.
Last month private equity company CVC Capital Partners became the majority owner in the company, taking over from BC Partners.
The UK business generated revenue of an estimated £45m in 2018, according to PRWeek UK’s Top 150 Consultancies table, employing around 240 people at the year end. In the UK, the firm represents 24 of the FTSE100, with stellar clients including Tesco and RBS.
Teneo declined to comment on the new appointment.