Writer and broadcaster Amy Lame has become London's first "night tsar" in a move to boost the after-dark entertainment scene in the capital.
The 45-year-old will work with police, businesses and the public to create a vision for the city's nightlife.
Ms Lame said she intended to "inspire a positive change in the way people think about the night-time economy".
The Conservatives at London Assembly said the post may be "less about the economy and more about ribbon cutting".
London's late-night industry is worth £26.3bn annually but research suggests this could rise to £28.3bn by 2029.
The broadcaster promoted Camden's live music venues and nightclubs as mayoress of Camden in 2010 and is known for campaigning to save renowned LGBT venue the Royal Vauxhall Tavern.
The former BBC Radio London co-presenter also co-founded and hosts the Olivier award-winning comedy theatre Duckie at the Royal Vauxhall Tavern and was chosen to the new post from 200 candidates.
Ms Lame said she would hold monthly surgeries to speak to businesses, police, councils, night-time workers and Londoners to create a safer and more responsible nightlife.
She said: "For too long, the capital's night-time industry has been under pressure - music venues and nightclubs in particular are closing at an alarming rate."
Fabric nightclub, one of the UK's best-known clubs, lost its licence and shut down over what Islington Council said was a "culture of drugs".
In response to the closure, Mayor Sadiq Khan claimed the capital had lost 50% of its nightclubs and 40% of its live music venues in the past eight years.
Mr Khan said: "The recent closure of the world-famous nightclub Fabric and the threats facing other venues across the capital show why Amy will be a much-needed ambassador for the city after dark."
Gareth Bacon, Conservative London Assembly member, said appointing a "celebrity over someone with more experience running a business in the night-time economy is a decision the Assembly will need to seriously scrutinise".