M1

the Crab Nebula, also known as Messier object M1
ATC code M01 Anti-inflammatory and antirheumatic products, a subgroup of the Anatomical Therapeutic Chemical Classification System

Primary motor cortex or M1, a symbol of the primary motor cortex in mammals in neurology
M1 protein, a matrix protein of the influenza virus
Muscarinic acetylcholine receptor M1, a receptor in the human autonomic nervous system
British NVC community M1, Sphagnum auriculatum bog pool community
20-O-beta-D-glucopyranosyl-20(S)-protopanaxadiol, a ppd-type monoglucoside ginsenoside metabolized by intestinal bacteria
M1 macrophage
, a phenotype of macrophage

Roads and railways

Bucharest Metro Line M1, part of the Bucharest Metro, Romania
Chesapeake and Ohio class M-1, a steam-turbine locomotive
Line 1 (Budapest Metro)
, the first line of Budapest Metro, Hungary
LNER Class M1
, a class of British steam locomotives
M-1 Rail Line
, now the QLine, streetcar service in Detroit
M1 (Copenhagen)
, part of the city's Metro system, Denmark
M1 (Istanbul Metro), a light railway system in Istanbul, Turkey
M1 (Lausanne Métro)
, part of the Lausanne Metro in Switzerland
M1 (Paris Métro), the first rolling stock on the Paris Metro in 1900
M1 (İzmir Metro)
M1/M3 (railcar), a series of electric multiple unit cars on the Long Island Rail Road and Metro-North Railroad
Metro M1 (Prague), metro kit M1, which is used on line C of the Prague Metro
Milan Metro Line 1
M1 (Warsaw), the first metro line of the Warsaw Metro
PRR M1
, a class of steam locomotive
M series (Toronto subway), former rolling stock of the Toronto subway
M1 Metro North West & Bankstown Line
, Sydney Metro service

M1 road (Australia)
, different sections of the A1 highway
- M1 (New South Wales)
- M1 (Queensland)
- M1 (Victoria)
Metroad 1
, a road in Sydney, Australia
M-1 (Michigan highway), a road in the United States that runs from Detroit northwesterly to Pontiac
M1 highway (Belarus), a road connecting the border with Poland and the border with Russia
M1 highway (Russia), a road connecting Moscow and the border with Belarus
M1 (East London), a Metropolitan Route in East London, South Africa
M1 (Johannesburg), a Metropolitan Route in Johannesburg, South Africa
M1 (Pretoria), a Metropolitan Route in Pretoria, South Africa
M1 (Durban), a Metropolitan Route in Durban, South Africa
M1 (Port Elizabeth)
, a Metropolitan Route in Port Elizabeth, South Africa
M1 motorway (Hungary), a road connecting Budapest and Győr
M1 motorway (Northern Ireland), a road connecting Belfast and Dungannon
M1 motorway (Pakistan)
, a 155 km (96 mi) road connecting Peshawar and Rawalpindi
M1 motorway (Republic of Ireland), a road connecting Dublin to the border with Northern Ireland
M1 motorway, a road in England connecting London and Leeds
Highway M01 (Ukraine), a road connecting Kyiv and the border with Belarus
M1 Road (Zambia)

M1 category vehicle
, a classification of passenger vehicles under the United Nations Economic Commission for Europe

Hakuto-R Mission 1, private Japanese lunar landing mission
M-1 (rocket engine)
, the largest liquid Hydrogen and LOx rocket engine ever designed
Martin M-1, glider
Matteson M-1, glider
Miles M.1 Satyr, a 1930s British single-seat aerobatic biplane
Verville-Sperry M-1 Messenger - 1922

M-1 Global or M-1 Mixfight, a mixed martial arts sports organization
M-1 visa, a vocational training student visa for the USA
M1 (Singaporean company), a telecommunications company in Singapore
M1 World Championship, the first esports world championship for the mobile game Mobile Legends: Bang Bang held in 2019
M1, a difficulty grade in mixed climbing