Simkin glider gun is a glider gun found by Michael Simkin on April 28, 2015. It consists of a Herschel running in a loop made of two B60 conduits, producing infinite copies of the first natural glider.

In terms of its 36 cells (if one of the two streams is suppressed by an eater 1) it is the smallest known gun, sharing the record with the Gosper glider gun.

In the 29-cell double-barrelled form (shown in the infobox), as well as the pseudo-period boat-bit form, it is the absolute record holder. Its smallest known predecessor has only 21 cells.