The SIG Sauer P226 and its variants are in service with numerous law enforcement and military organizations worldwide.

[4][5] In 1975, SIG entered into an agreement with German gun manufacturer J.P. Sauer & Sohn to develop and market a new handgun which became the P220.

[7][8] According to a GAO report, Beretta was awarded the M9 contract for the 92F due to a lower total package price.

[9] The P226 cost less per pistol than the 92F, but SIG's package price with magazines and spare parts was higher than Beretta's.

[16] The SDM XM9 is a variant of the NP22 chambered in 9×21mm for countries that don't allow any pistol calibers that are only for the military and police.

[19] The first Naval Special Warfare inspired P226 pistols to be offered to the public were the NSW Commemoratives, issued in early 2004.

SIGARMS raised $100,000 for the Special Operations Warrior Foundation through the sale of these NSW serialized pistols.

The pistol with the serial number NSW0001 was sold during a live auction on the US-wide syndicated Laura Ingraham radio show for an additional $25,000.

Later produced commercial versions added a universal rail for accessory attachments while retaining the anchor of previous models, but do not have the SIGLITE Night Sights.

[21] The gun was discontinued from the P226 model lineup at the end of 2010 but the E2-style grip system has been adopted on and carried over to other P226 variants.

A compact version of the P226, the P228 is in use with various law enforcement agencies and also with the United States Armed Forces, where it is designated as the M11.

In the summer of 2012, SIG Sauer announced they were releasing the M11A1, which is essentially the milled-slide P229 chambered in 9mm with P228-labeled grips, a short reset trigger, SIGLITE tritium night sights, Mec-Gar 15-round magazines, and a military style smart tag and serial number.

[24] On January 19, 2017, it was announced that the SIG Sauer P320 Compact (M18) had been selected to replace the M11 as the U.S military service pistol.

One factor in winning the Modular Handgun System competition was the ability to employ 9mm Parabellum, .357 Sig or .40 S&W cartridges within the same basic frame.

Developed specifically for the US market and assembled with both German and US-made parts, the P229 features a heavier slide to tolerate more powerful rounds the P228 is incapable of using.

Most of the above-mentioned factory variants of the P226 are also available for the P229, including the Equinox option, Elite lineup, as well as a SAS GEN 2 model.

The 9mm model (both railed and non-railed) can be converted to .22 LR, but in the past its receivers were not designed to provide the space needed for handling the larger rounds of .357 SIG and .40 S&W.