The daughter of Holby City actor John Michie, was found dead in a wooded area on the edge of the festival site at Lulworth Castle in Dorset.
Her body was discovered just before 1am on September 11 last year.
Ceon Broughton, 28, of Enfield, north London, is due to appear before Poole Magistrates’ Court on Saturday, Dorset Police said.
He has been charged with manslaughter by gross negligence.
An initial post-mortem examination carried out shortly after her death showed no clear signs of an assault, and further examinations have been carried out, including toxicology tests.
Senior investigating officer Neil Devoto, of Dorset Police’s major crime investigation team, said: “Following a detailed investigation, we have consulted with the Crown Prosecution Service, which has this evening authorised a charge of manslaughter.
“It is important to stress – as is typical in such circumstances – that it would be entirely inappropriate for Dorset Police to comment further ahead of the trial.
“It is also important that nothing is published online or on social media that could affect a future criminal case. It is vital that the justice system is allowed to follow its course.
“Louella’s family has been updated with this development and our thoughts remain with them at this very difficult time.”