However, there is an increased risk in certain groups, the University of Glasgow research found.
Overall, veterans were at no greater risk than the general public, whilst both Falklands and Gulf War veterans had a lower risk of suicide.
The team studied veterans in Scotland who served between 1960 and 2012.
The study compared suicide risk among 56,205 veterans born between 1945 and 1985 with 172,741 matched non-veterans.
While overall there was no significant difference in the figures for veterans and non-veterans, the risk increased for:
Young veterans were not found to be at increased risk - a finding at odds with an earlier study by the Centre for Suicide Prevention which suggested that ex-servicemen under the age of 24 had a much higher rate of suicide.
Asked to explain the differences, lead researcher Dr Beverly Bergman said the two studies used different data and methodologies.
She said: "We have a smaller number of veterans but have studied them over a longer time period.
"In our study we had only two veterans under the age of 25 who died by suicide. The two studies are not directly comparable."
Dr Bergman said there was growing evidence that there is no overall difference in long-term risk of suicide between veterans and non-veterans in the UK.
She added: "This is an important study which provides reassurance that military service in the last 50 years does not increase people's risk of suicide overall, but it draws our attention to those people whose increased risk may be overlooked, such as older veterans and women veterans.
"It also confirms that early service leavers have a slightly increased risk but that may not manifest itself until middle age."
The study, which used data from the Scottish Veterans Health Study to examine deaths classified as due to suicide or self-harm, is published in Occupational Medicine.
People who have served in the armed forces in the past 50 years are not at greater risk of suicide than those who have not, according to a new study.