S27 may refer to:
Aviation Blériot-SPAD S.27, a French biplane airliner Kalispell City Airport, in Flathead County, Montana, United States Short S.27, a British military trainer Sikorsky S-27, a Russian biplane bomber
Rail and transit S27 (Long Island bus), United States S27 (Munich), a line of the Munich S-Bahn, Germany S27 (Südostbahn), a railway service in Switzerland S27, an Aargau S-Bahn line in Switzerland and Germany Rankoshi Station, in Hokkaido, Japan
Other uses 40S ribosomal protein S27 British NVC community S27, a swamps and tall-herb fens community in the British National Vegetation Classification system County Route S27 (California) , a submarine of the Royal Navy S27: Take off immediately all contaminated clothing, a safety phrase Sulfur-27, an isotope of sulfur , a submarine of the United States Navy