S&W J Frame for me it’s as small that I feel comfortable with bringing into a defense position without fumbling and loss of speed. My 351C coming in at 11 ounces Makes for great small gun.
For about 10 years my smallest gun was a Kel Tec PF9 (9mm), which gave way a few years back to a Seecamp LWS 32 (.32 ACP), which as of last year or so gave way to my Bauer .25 Automatic (.25 ACP). This is the smallest hand gun I own, or have ever owned.
Beretta 950. Or, maybe a Jennings .22....I am so ashamed. It was decades ago, honest, I was young and stupid. I swear.
I am a huge mouser fan. The Walther Model 9 is the smallest commercial autoloader followed closely by the Baby/Bauer. Here's a shot that shows some of the guns mentioned in the thread.
Smallest revolver: NAA Sidewinder 22 Magnum, picked it up at a pawn shop. Smallest autoloader: Raven P-25, my grandmother bought it new in the mid 1970's.
I have a Remington vest pocket derringer. It's very tiny. Black powder 22 rimfire. 3 digit serial # Made somewhere between 1863-65. Spring is still strong, refinished in the 1800's.
Beretta Bobcat Belgium Bulldog Still haven't shot the Belgium yet, reminded me to get some ammo from that guy up north...
It depends on how you measure them. Either an AMT .380 Backup, a Cobra Derringer in .22 Mag or a NAA Mini convertible .22.
A few people mentioned the 2mm pinfire guns. I just wrote a little article about them: https://aaronnewcomer.com/2mm-pinfire-guns-and-cartridges/ They've got to be about the smallest and definitely the smallest in my collection.
I had a Bernardelli VB like Pete's except .22 Short. I thought about the .22 Long but ammo was getting scarce even then. Not a big enough frame for Long Rifle.
I carry full size guns most of the time,but one of these or both are always on my person.The main point is have a gun