Sweden is an exporter of submarines and does not import them.
Producing submarines for the Swedish Navy since 1914, the Swedish shipyard Kockums did not begin exporting its vessels until the 1980s, in large part due to Sweden's policy of neutrality in international conflicts. This neutrality position, in turn, has led some countries to view Sweden as an unreliable supplier.  Sweden's change in export behavior in the 1980s has been attributed to increasing development costs, which were amplified by its strategy of frequently introducing new classes, but only producing a few boats in each class. To retain the ability to develop new boats continuously without facing increasingly prohibitive costs, Sweden decided to export its vessels to achieve economies of scale. 
In 1999, Kockums was incorporated into Germany's Howaldtswerke-Deutsche Werft (HDW), and as of 5 January 2005 is part of ThyssenKrupp Marine Systems (TKMS).
Kockums offers three submarine classes for export:
- Gotland-class: hybrid diesel-electric/AIP patrol submarines, with an AIP system based on the Stirling engine;
- Västergötland-class: diesel-electric patrol submarines;
- Collins-class: diesel-electric, ocean-going, long-range patrol submarines, designed for the Australian Navy.
Submarine Table for Sweden
In 1987 Kockums was granted a contract to supply the Australian Navy with six Collins-class vessels, and formed the Australian Submarine Corporation (ASC) to construct the submarines locally. Kockums held 49% of ASC's shares, while the Australian government controlled the remainder. When Kockums became part of HDW in 1999, the German company was interested in acquiring ASC as well, and nearly reached an agreement to do so with Australian authorities.  However, the Australian government instead decided to acquire Kockums' shares of ASC with the intent of subsequently selling the shares as a complete package in order to maintain access to the U.S. technology used in the Collins-class submarines.  Subsequently, Kockums and the Australian government became embroiled in a legal battle over payment for welding repairs made to one of Australia's submarines, and intellectual property rights for future upgrades.  The dispute was finally settled in 2004, but the Australian government has had difficulties privatizing ASC and has yet to sell the company. 
Kockums attempted to market an export version of the Gotland-class to Thailand, but the deal fell through as a result of financial difficulties experienced by the Southeast Asian country.  The company was also a finalist for a sale to India, a deal HDW later secured.  More success was achieved with Singapore, which acquired a total of four modernized former Royal Swedish Navy Sjöormen-class boats (Challenger-class in Singapore) in the 1990s, and ordered two Västergötland-class vessels (Archer-class in Singapore) in November 2005.  The two Västergötland-class boats, which first entered service with the Royal Swedish Navy in 1986 and 1987, underwent modernization with AIP systems and conversion for tropical water operation before being delivered to Singapore.  The contract also includes a logistics package and training for the crews by the Swedish Navy in Karlskrona.  In December 2011 the first submarine, the RSS Archer (ex-HMS Hälsingland), was commissioned into Singapore's Navy.  The RSS Swordsman was commissioned in April 2013. 
Kockums also refits deployed submarines with its Stirling AIP system via a plug-in.  For example, it refitted a former Swedish Navy Näcken-class submarine with AIP and leased it to the Danish Navy from 2001 to 2004.  In July 2005, Kockums announced that it would produce Stirling engines for the Japanese Maritime Self-Defense Force (JMSDF), which decided to include AIP on all new boats.  While Kockums is supplying the engines, Kawasaki Heavy Industries is assembling the AIP systems.  The first submarine of the JMSDF equipped with Stirling engines, the Soryu (SS-501) was laid down in March 2005, launched in December 2007, and commissioned in March 2009. Four more Soryu-class boats have since been commissioned at a rate of roughly one per year. 
In the early 2000s, Kockums developed the Viking concept, a hybrid diesel-electric/AIP (Stirling) patrol submarine initially intended to replace aging units in the Danish, Swedish, and Norwegian navies.  Kockums initially cooperated on the vessels with Denmark's Odense Steel Shipyard using Danish, Norwegian and Swedish funding. However, Norway opted out of the project in 2003, while Denmark decided in June 2003 to cease funding the project in its 2005 to 2009 Defense Plan, throwing Viking's financing into question.  In June 2004, moreover, the Danish parliament decided to stop operating submarines altogether. 
Although the failure of the Viking project ended the prospect of cooperation with other Nordic countries, Kockums received a contract to design a new submarine, called the A26, for the Swedish Navy.  The A26 features the Stirling AIP system and will be designed with advanced stealth technologies for performing intelligence missions.  Kockums has yet to begin construction, but if it follows through on the order for Sweden the company could market the A26 for export as well.
 Anthony Watts, Jane's Underwater Warfare Systems: 2003-2004 (Coulsdon: Jane's Information group, 2002), pp. 31-47.
 Richard Scott, "Viking submarine to steer two-nation course," Jane's Defence Weekly, www.janes.com, 4 June 2003.
 Thomas Dodd, "Danes improve airlift in 2005-09 defence plan," Jane's Defence Weekly, www.janes.com, 23 June 2004.
 "Näcken returns" International Defence Review, 1 December 2004, www.janes.com.
 "Stirling AIP conversion," Kockums, https://kockums.de.
 "Submarines," Kockums, https://kockums.de.
 Derek Wollner, "Procuring change: how Kockums was selected for the Collins class submarine," Research Paper No. 3, 2001-2002, Information and Research Services, Department of the Parliamentary Library, www.aph.gov.au, p. 7.
 Hans Harboe-Hansen, "Viking—the future Nordic submarine?" Naval Forces, 1998, Vol. 19, No. 5, pp. 30-34; in ProQuest Information and Learning Company, https://proquest.umi.com.
 P. Lewis Young, "The Royal Australian Navy's new submarine selection," Asian Defence Journal, August 1984, pp. 52; in Derek Wollner, "Procuring change: how Kockums was selected for the Collins class submarine," Research paper No. 3, 2001-2002, Information and Research Services, Department of the Parliamentary Library, www.aph.gov.au, pp. 7.
 "The Viking submarine project," Military Technology, 2002, Vol. 26, No. 18, pp. 32-34; in ProQuest Information and Learning Company, https://proquest.umi.com.
 John Arne Moen, "Unwise to drop submarine project," Aftenposten, 27 June 2001; in "Norway's Navy chief opposes quitting joint-Nordic Viking submarine project," FBIS Document EUP20010628000485.
 Max Blenkin, "Fed: Government to continue discussions with Germans over subs," AAP Newsfeed, 6 April 2000; in Lexis-Nexis Academic Universe, https://web.lexis-nexis.com.
 "Background Information," Australian Submarine Corporation (ASC), www.subcorp.com.au.
 Georffrey Barker, "US warns of conflict over subs," Australian Financial Review, 4 April 2000; in "Daily views Australian Sub Corporations future, US ties," FBIS Document SEP20000403000121.
 "Handelsblatt: USA gegen Kauf australischer Werft durch HDW," AFX News Agency, 11 April 2000; in Lexis-Nexis Academic Universe, https://web.lexis-nexis.com.
 Michel Richardson, "Australia struggles to get its submarines shipshape," International Herald Tribune online edition, www.iht.com.
 "Top secret propellers sent without designer's permission," AAP Newsfeed, 15 March 2001; in Lexis-Nexis Academic Universe, https://web.lexis-nexis.com.
 Gavin Lower, "Subs' secret design given to Americans," The Advertiser, 16 March 2001; in Lexis-Nexis Academic Universe, https://web.lexis-nexis.com.
 David Lague, "Sweden goes to war: Australia blasted over submarine secrets," Sydney Morning Herald, 29 December 2000; in Lexis-Nexis Academic Universe, https://web.lexis-nexis.com.
 "Breakthrough in Japan for Stirling AIP," Kockums, 11 July 2005, https://kockums.se.
 "Kockums receives Singapore order to two submarines," Kockums, 4 November 2005, https://kockums.se.
 "RSN Acquires Vastergotland-Class Submarines," Defence Talk, 4 November 2005, www.defencetalk.com.
 "The Way Ahead – for Kockums A26," Kockums, 26 August 2011, www.kockums.se.