R1, R.I., R01 or R-1 may refer to:

Biology

* R1 plasmid, a plasmid found in E Coli * ATC code R01 ''Nasal preparations'', a subgroup of the Anatomical Therapeutic Chemical Classification System * Haplogroup R1 (Y-DNA), a human Y-chromosome DNA haplogroup * The Insect wing#Venation, R1 vein in insect wings

Computing

* DeepSeek-R1, an open-source large language model released by DeepSeek in January 2025 * R1 (expert system), a 1978 expert system written by John McDermott * .r01, a RAR file extension * an alternate name for the Rice Institute Computer, an innovative computer extant at Rice University from 1959 to 1971

Military equipment

* R-1 tank, a Romanian tank from World War II * R-1 (missile), a post World War II Russian rocket * AEG R.I, a 1918 German super-heavy bomber design * DFW R.I, a 1916 German prototype bomber aircraft * HMS Caprice, a destroyer originally designated with Pennant Number R01 * Linke-Hofmann R.I, a World War I German prototype bomber aircraft * Polikarpov R-1, a Soviet Union copy of the 1931 British Airco DH.9A light bomber aircraft * USS R-1 (SS-78), a 1918 United States Navy R-class coastal and harbor defense submarine * a South African made version of the FN FAL battle rifle * a version of the 1942 German Rheintochter ground-to-air missile * Raytheon Sentinel, Sentinel R1, a British airborne radar platform * a Romanian designation of the Czechoslovak-designed tankette AH-IV

Transportation

Automobiles

* Jaguar R1, a British 1999 Formula One racing car * Javan R1, a British sports car * Nuro R1, an American autonomous van * Ora R1, a Chinese electric city car * Praga R1, a Czech sports car * Rivian, R1S and R1T, an American electric mid-size SUV and pickup truck * SIN R1, a Bulgarian sports car * Subaru R1, a Japanese city car

Aviation

* Beriev R-1, a 1952 Soviet turbojet-powered flying boat * International Air Transport Association code for Sirin (airline)

Motorcycles

* Yamaha YZF-R1, a motorcycle

Rail

Lines

* R1 (SEPTA), a former commuter rail line in Philadelphia, Pennsylvania, which was split into: ** Airport Line (SEPTA), or R1 Airport line ** SEPTA Main Line ''(R1 Glenside)'' Also called the Glenside Combined * R1–RG1 (Rodalies de Catalunya), a commuter rail line in Catalonia, Spain * R1 King George Blvd, RapidBus line in Surrey (Metro Vancouver, British Columbia, Canada) * R1 (RER Vaud), an S-Bahn line in the canton of Vaud

Individual locomotive and multiple-unit classes

* LCDR R1 class, a class of 0-4-4T steam locomotives built by the South Eastern and Chatham Railway to modified LCDR design in 1900 * LNER Class R1, a class of British steam locomotives * PRR R1, a 1934 American single prototype electric locomotive * R1 (New York City Subway car), an American rapid transit multiple-unit * SECR R1 class, a class of 0-6-0T steam locomotives rebuilt by the South Eastern and Chatham Railway from the SER R class between 1910 and 1922

Roads

* R1 expressway (Czech Republic), an expressway in the Czech Republic * R1 expressway (Slovakia), a road connecting Trnava and Banská Bystrica * R1 ring road (Belgium), a ring road around Antwerp * R-1 motorway (Spain), a future radial motorway connecting Madrid and El Molar * R1 road (Zimbabwe), a road connecting Beitbridge and Harare * Radial Road 1 or R-1, an arterial road of Manila, Philippines

Other

* R01 grant, a form of competitive funding issued by the National Institutes of Health in the United States * R1: Explosive when dry, a risk phrase * R-1 Federation * Rogue One, a 2016 film * R1 Multi-frequency signaling, a telephony control technique * R1 (nuclear reactor), the first nuclear reactor of Sweden * R1 space, R₁ space in topology, in mathematics * R-1 visa, a non-immigrant Visa (document), visa which allows travel to United States for service as a minister or other religious occupation. * DSC-R1, a 2005 Sony Cyber-shot R series camera * R1, a brand sold by Imperial Tobacco * Region 1, the DVD region code for United States, Canada, Bermuda, U.S. territories * Research I university, a designation of U.S. universities engaged in the highest levels of research activity * BBC Radio 1, a national radio station in the United Kingdom * Radio One (New Zealand) a New Zealand student radio station * Samsung YP-R1, a digital audio player * Rabbit r1, an AI-based personal assistant device