The Model 29 was offered with 4", 5", 6½", 8⅜" and, later, 10⅝" barrel lengths as standard models. Other barrel lengths were available either by special order from Smith & Wesson's Custom Shop or custom built by gunsmiths. The 5" barreled variant had a full length underlug. Finish options available included a highly polished blued or nickel-plated surface.

The Model 29, based on S&W's N (large) revolver frame, was first introduced in 1955. It remained primarily the province of handgun enthusiasts, some law enforcement personnel and hunters until 1971, when Clint Eastwood made it famous as "the most powerful handgun in the world" in the movie Dirty Harry.

Although the Model 29 has never been the most powerful handgun in the world as stated in the movie, the Model 29 was among the most powerful at the time, at least as far as commercially available weapons go. Whether the phrase from the movie was an accurate statement when it was made is subjective to several factors such as overall terminal ballistics, external ballistics, or some combination of other factors. After the movie's release retailers had trouble keeping the Model 29 in stock.

At the time of its introduction, the model 29 was the most powerful production handgun. There were, of course, a number of custom, or wildcat, calibers that were more powerful, as in the old Howdah pistols of the 19th century. Elmer Keith's achievements in maximizing the power and performance of the .44 Special was the inspiration and driving force behind the introduction of the .44 Magnum by Smith & Wesson. His intention for the new round was to be used in sidearms for hunters of large, dangerous game, rather than for self defense, though with today's specialty cartridges, it can be a good defensive round.

It will also chamber and fire .44 Special cartridges, as the .44 Magnum was developed from the .44 Special. The Magnum case is slightly longer to carry more propellant. This also prevents Magnum rounds from being chambered and fired in handguns chambered for the .44 Special.

In the late 1990s, Smith and Wesson discontinued production of many models of revolvers, including the 'basic' Model 29; since then, at various times, the model, in limited or 'custom' configurations, has been manufactured.

Introduced in 1978, the Smith and Wesson Model 629 is a stainless steel version of the Model 29.

The 629 model designation derives from Smith and Wesson's practice of denoting a stainless steel version of one of their already existing designs by placing a 6 in front of the model number of the original weapon.

The 629 Classic variant features a full length barrel underlug.

Some S&W model 29s were rebuilt by the AAI Corporation to make the Quiet Special Purpose Revolvers (QSPR). These had new, short, smoothbore barrels (35 mm / 1.375 inch), with .40" / 10mm bore, and with cylinder chambers reamed to accept special QSPR ammunition which externally resembled metal-cased .410-gauge shotgun shells but internally worked as a piston to trap the gases. This special ammunition was also made by AAI.This pistol was developed from 1967-1971 to be used by tunnel rats in the Vietnam War. The QSPR was tested on the battlefield in 1969, an improvement and testing program ran 1970 till 1971. At least officially it never entered service. The US withdrawal from Vietnam reduced interest in the QSPR weapon, and the program was ended about 1972.