More than 1,500 GP surgeries, hospitals, pharmacies and schools around the UK have been sent A3 posters and postcards to use in Mental Health Action Week, which runs from 11-17 April.
The charity aims to reduce the stigma attached to mental illness, as well as the fear and prejudice that can prevent people from seeking help for their mental distress.
"The prevalence of mental illness is one of the most powerful messages we have when we are trying to fight stigma. But a them-and-us attitude still exists," said Dr Andrew McCulloch, the foundation's chief executive.
"Clearly, the one-in-four figure is still not widely known."
The foundation is using this campaign to convince people that anyone - themselves, friends, relatives or work colleagues - can be affected by mental illness.
Design agency Uber created the designs, entitled 'I'm not coping' and 'Them and us'.
'I'm not coping' depicts the faces of four people in poses modelled on the Bohemian Rhapsody cover, each with a caption next to their mouths.
Three say they are doing OK, while the fourth says 'I'm not coping,' despite her glazed smile.
Celia Richardson, the charity's director of communications, said: "Stigma may encourage people to hide their feelings."
'Them and us' shows a variety of words representing people's moods. The words, ranging from 'great', 'happy' and 'fine' to 'panic', 'loss' and 'anxious', emerge from each other to show that everyone can recover from mental illness and that people's moods can alter at short notice.