Almost one in four (24 per cent) of young people say they feel at risk because of violence in their community, according to the Prince's Trust.
A total of 39 per cent of 16 to 25-year-olds say that news about increasing violent crime makes them concerned for their safety.
The survey of 2,162 young people from across the UK also found that two-thirds (68 per cent) think violent crime is a result of people reacting to what is happening in their home lives.
In 2014, there were 517 police-recorded homicides in England and Wales, but that increased to 732 in 2018.
In total, 46 homicide investigations have been launched in London in 2019 so far, with 20 of the victims aged 25 or under.
The youngest stabbing victim was 14-year-old Jaden Moodie, who was killed in Leyton, east London, in January.
The Trust's founder, the Prince of Wales, previously called for a renewed effort to "make a dent" in the scourge of knife crime and youth violence.
Prince Charles said in December: "There must be better ways if we're going to prevent all these appalling disasters and tragedies happening to so many people's families.
"This is a thing which seems unacceptable, frankly, we should say enough is enough, this time we really are going to make a dent in this for the sake of so many young, so many families."
Nick Stace, chief executive of the Prince's Trust, said: "It is of great concern to see that so many young people feel unsafe in their communities."