Two in five men aged between 20 and 59 do not ask for help when they need it because they prefer to try to solve problems themselves, a survey found.
Their campaign is supported by ex-footballer and boxer Leon McKenzie, who has spoken of his own past struggles in a “dark place”.
While more than three quarters of those surveyed said it is alright to admit when you are not feeling OK, a quarter of them felt their problems were not important enough to warrant calling a helpline.
The main problems causing men to struggle included debt or financial worries, relationship breakdown or family problems, loneliness or isolation and job loss or job-related problems, the charity said.
The Real People, Real Stories campaign, which is supported by National Rail, involves men who have overcome tough times sharing their stories to encourage those most at risk of suicide to get help.
Mr McKenzie said: “I know how tough it gets when you’re in that dark place. I’ve been there, not wanting to exist anymore.
“By sharing my story and supporting the campaign, I hope other men understand that you can climb back up with some help.
“It’s so important to seek help early on and Samaritans are here to listen.”
More than 50 local events are due to take place in England, Wales and Scotland to help promote the campaign.
Anyone seeking help can call Samaritans 24/7 free on 116 123 or visit Samaritans.org.