Kirk was one of the very few stars of the mid-20th century who did not normally smoke in his films, and if he'd been a smoker, he would have if the period of the movie allowed for it. (He wouldn't have smoked in
Spartacus
, for example.) But it's always struck me how rarely he's seen smoking in his movies, and then only a little.
I remember him smoking in one scene in
Ace in the Hole
(1951) and
Lonely Are the Brave
(1962), and I'm sure there were some others, but unlike most of his contemporaries he didn't smoke much. (Neither did a few other major stars, like James Stewart and Henry Fonda.)
And of course, in
A Letter to Three Wives
, Kirk, in his outburst denouncing the sins of commercial radio, lists a bunch of problems people may be worried about in real life one of which is, "Will your cigarettes give you cancer?" This was in
1949
! Of course, Kirk was only reciting dialogue written by Joseph L. Mankiewicz. But the very fact that the connection between cigarettes and cancer something that at that time had little evidence and which most people disbelieved was even mentioned 15 years before the Surgeon General's 1964 report on the subject is nothing short of amazing. In that case, who better to deliver the message than an actor who didn't smoke? (The other Douglas in that film, Paul, was always overweight and a very heavy smoker, and died of a heart attack at 52.)

He quit smoking when he was 50.

His trivia says he quit in 1950.

Awesome, good to know there's hope for those who quit. I hope too one day.

He had to learn to smoke for a role, then got hooked. He did finally quit, tho.

Oldest people who ever lived, they were all smokers.
"People get it wrong, but in today's world we don't live longer, we just die harder." -Bruce Willis

If this picture is any indicator, than yes
https://assets.mubi.com/images/cast_member/4668/image-original.jpg?1427728700

It Is safe to say yes Definition of troll on IMDb - anyone who expresses a view different to mine.