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.

Prime Minister Matteo Renzi has pledged â‚¬50m (Â£42m) in funds for rebuilding.
At least 268 people are now known to have died and 400 were injured. Teams have continued to search the rubble of toppled buildings for a second night.
However, hundreds of aftershocks have hampered the efforts of the 5,000 rescuers.
Another magnitude-4.7 tremor struck early on Friday.
In addition to the funds, Mr Renzi cancelled taxes for residents and announced a new initiative, "Italian Homes", to tackle criticism over shoddy construction.
But he also said that it was "absurd" to think that Italy could build completely quake-proof buildings.
It follows criticism in the Italian press over building standards in high-risk areas. Some of the buildings that collapsed had recently been renovated.
Historic towns do not have to conform to anti-quake building regulations, which are also often not applied when new buildings are put up.
The 6.2-magnitude quake hit in the early hours of Wednesday, 100km (65 miles) north-east of Rome in mountainous central Italy.
The worst affected towns - Amatrice, Arquata, Accumoli and Pescara del Tronto - are usually sparsely populated but have been swelled by tourists visiting for summer, making estimates for the precise number missing difficult.
More than 200 people died in Amatrice alone.
At least three Britons died in the quake, a local official in Amatrice told the BBC. The Romanian government said 11 of its citizens were missing.
Bodies are still being found in the town, including one discovered in the rubble of the Hotel Roma in the city late on Thursday.
An official with the fire department, Lorenzo Botti, admitted they were facing a race against time.
"The chances of finding people alive in these conditions, in this type of setting, well, it's challenging," he said.
But other rescuers said there was still hope, noting that one survivor was pulled from ruins in L'Aquila in 2009 three days after an earthquake that killed more than 300 people.
Search teams have asked locals to disable their wi-fi passwords to help rescue workers communicate more effectively.
Police have also arrested a man for attempting to break into and loot an empty home in the town, Ansa reported.
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.
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Italy has declared a state of emergency in the regions worst hit by Wednesday's earthquake as hopes of finding more survivors fade.