HMS E26 was a British E-class submarine built by William Beardmore and Company, Dalmuir.

HMS E26 was lost with all hands in the North Sea, probably in the vicinity of the eastern Ems, on or about 3 July 1916.

British E-class submarines had fuel capacities of 50 long tons (51 t) of diesel and ranges of 3,255 miles (5,238 km; 2,829 nmi) when travelling at 10 knots (19 km/h; 12 mph).

E26 was armed with a 12-pounder 76 mm (3.0 in) QF gun, mounted forward of the conning tower.

[4] E-Class submarines had wireless systems with 1 kilowatt (1.3 hp) power ratings; in some submarines, these were later upgraded to 3 kilowatts (4.0 hp) systems by removing a midship torpedo tube.