Among them are Matt Jones, a personal trainer, and Worthing Utd footballers Matthew Grimstone and Jacob Schilt.
Mr Grimstone, 23, the first-team goalkeeper, and Mr Schilt, also 23 and a “tenacious midfielder”, were on their way to play a home game against Loxwood FC at 3pm when they were caught up in the crash.
In an emotional tribute, Mr Grimstone’s parents Sue and Phil and brothers David and Paul called him the “kindest person you could ever meet”.
Sussex Police Assistant Chief Constable Steve Barry said police could not yet formally identify any of those who had died.
Mr Barry said: “This has been an enormously traumatic incident and our thoughts are with everyone who has been affected, from those who have suffered bereavement to those in the local community who are deeply shocked.”
He added: “Sadly, as a result of our initial work at the site, which has continued overnight, and inquiries following calls to the emergency services from worried families and friends, we have now identified 11 people who we are treating as highly likely to have died in this tragedy.” Mr Barry also warned that the death toll could rise further still.
He said: “The scene itself is incredibly large. A lot of specially-trained officers are sifting, as we speak, so we do need to keep an open mind but from what we have seen at this stage it is possible that we will find more fatalities.”
Investigators are keeping “an open mind” about who has been involved in the crash as they continue to receive calls from worried friends and relatives.
The deadly plane crash at the Shoreham Airshow was an event as likely to happen as being struck by lightning, according to an aviation expert.
Former pilot and RAF flying instructor David Learmount told Sky News that such crashes are extremely rare and “horrifically unlikely”.
The pilot of the Hawker Hunter jet that crashed at Shoreham is a skilled aerobatic flyer who is a regular at air shows up and down the country.
Andy Hill flies for British Airways and is a highly skilled former RAF instructor with more than 12,000 hours of flying experience.
The 51-year-old is in a critical condition in hospital after his plane slammed into the A27 in West Sussex, ploughing through cars on the busy road as it burst into a huge fireball.
At least one person has died when two small planes collided in the air and crashed at an airshow in northern Switzerland.
The two planes were part of a formation of three and crashed just before 11.30am local time after they touched each other in the air, according to Meinrad Stoecklin, a spokesman for police in Basel-Landschaft.
The airshow in the village of Dittingen, near Basel, was interrupted as rescue teams raced to the scene of the crash, police said.
It was not immediately clear if there were any more injured people.
Swiss media reported that one pilot managed to escape by parachute.
The two planes were part of a formation of three planes, but the third plane of the formation was not involved in the crash and landed safely, they reported.
It was a bad week for air disasters across the world. Last Thursday, two planes carrying dozens of parachutists collided in midair over western Slovakia, killing seven people, with 31 others on board surviving by jumping out with their parachutes, officials said.