We present a large-scale, volume-limited companion survey of 245 late-K to mid-M (K7-M6) dwarfs within 15 pc. Infrared adaptive optics (AO) data were analysed from the Very Large Telescope, Subaru Telescope, Canada–France–Hawaii Telescope, and MMT Observatory to detect close companions to the sample from ∼ 1 to 100 au, while digitized wide-field archival plates were searched for wide companions from ∼ 100 to 10 000 au. With sensitivity to the bottom of the main sequence over a separation range of 3 to 10 000 au, multiple AO and wide-field epochs allow us to confirm candidates with common proper motions, minimize background contamination, and enable a measurement of comprehensive binary statistics. We detected 65 comoving stellar companions and find a companion star fraction of 23.5 ± 3.2 per cent over the 3 au to 10 000 au separation range. The companion separation distribution is observed to rise to a higher frequency at smaller separations, peaking at closer separations than measured for more massive primaries. The mass ratio distribution across the q = 0.2–1.0 range is flat, similar to that of multiple systems with solar-type primaries. The characterization of binary and multiple star frequency for low-mass field stars can provide crucial comparisons with star-forming environments and hold implications for the frequency and evolutionary histories of their associated discs and planets.