Countries and entities that use or have used the Glock, not including about a Bazillion other police forces in the US and around the world:
Country                Organization      Model
Algeria Département du Renseignement et de la Sécurité and Special Intervention Group[93]   17
Australia             Australian Federal Police[94]      17, 19, 26
Corrective Services NSW,[citation needed] New South Wales Police Force,[95][96] Queensland Police Service,[96] Western Australia Police,[96] and Northern Territory Police[96][97]            22, 23, 27
Tasmania Police and the Australian Border Force[98]       17
Austria Austrian Armed Forces[99][100][101]     17 (as Pistole 80)
Azerbaijan         160 Glock pistols purchased in 2013. Used by Azerbaijani Special Military Services[102]   19
Bangladesh        Numerous law enforcement agencies and Bangladesh Army[103]            17, 22, 23
Belarus                "Almaz" antiterrorist group[104]               17
Belgium               Federal and local police forces[105]         17, 19, 26
Brazil    Federal Police Department - Departamento de Polícia Federal (DPF)[106]             17, 19, 26
Federal Highway Police - Polícia Rodoviária Federal (PRF)[107]    17, 17MOS, 26
Canada                British Columbia Conservation Officer Service,[108]         —
Quebec Safety - Sûreté du Québec (SQ)[100]     17, 19, 26
Royal Canadian Mounted Police (RCMP) [only Canadian Air Carrier Protective Program (CACPP) members]          19
Ontario Provincial Police (OPP)[63]          17M
Chile     [109]      17
Colombia            "Gaula EJC" Army antiextortion and antikidnapping group[104]  17
Croatia [109]      17
Denmark            Slædepatruljen Sirius special forces[110]              20, 26
Czech Republic Nonstandard sidearm issued to personnel on international deployments[111]   17
601st Special Forces Group[112]                17
Ecuador               National Police[100]        17
Various special police units such as the GOE and GIR[100]             17
Fiji         Tactical Response Unit[113]        —
Finland                Border Guard[114]          —
Defence Forces[114]      17 (as 9.00 PIST 2008)
Department of Corrections (Vankeinhoitolaitos)[114]     —
Primary service firearm of the police[115]            —
Estonia                Police service pistol.[116]             —
France Certain naval and airborne units of the French Armed Forces:[101][117] French Army Special Forces Brigade, Commandos Marine (France), Research sections of Gendarmerie Nationale, National Gendarmerie Intervention Group, Recherche Assistance Intervention Dissuasion, Groupes d'Intervention de la Police Nationale, Service de Protection des Hautes Personnalités, Brigade de recherche et d'intervention, Groupe de sécurité de la présidence de la République     17, 19, 26, 34
Georgia               Mainly used by GSOF and some MIA units.[100][101]     17, 21, 26
Germany            GSG 9 of the German Federal Police German commando frogmen of the Bundeswehr under the designation P9[118]        17
Greece                EKAM[119]         21
Greenland         Siriuspatruljen[120]        20
Hong Kong         Hong Kong Police Force (including special units such as SDU, CTRU, ASU and SBDIV),[100] ICAC and Hong Kong Customs   17, 19
Iceland                Iceland Crisis Response Unit (ICRU)[121][122][123]          —
Icelandic National Police[121][122][123]                —
Víkingasveitin[121][122][123]     —
India     Maharashtra Force One[124][125]           17, 19
National Security Guards, MARCOS and Para Commandos[100][126]       17, 26
Special Protection Group (replaced with FN Five-seven in 2008)[127]      17
Indonesia           [109]      17
Iraq       Iraqi security forces (largest Glock user, purchased 125,163 pistols)[128][129]     19
Israel    Israeli Defense Forces, Israel Police, Shin Bet[101]            17, 19
Jordan Royal Guard[100]             —
Kosovo                Kosovo Police, Kosovo Security Force[130][131]                17
Latvia   Latvian Military[101][132]             17
Lebanon             [109] Used by Lebanese republican guards, military intelligence forces and by some members of the Lebanese Special Operations Command brigades             17
Liberia  [109]      17
Lithuania             Lithuanian Armed Forces[101][133]         17
Lithuanian Police[134]    17, 19, 26
Luxembourg     Luxembourg Army[135]                17
Unité Spéciale de la Police of the Grand Ducal Police[136][137]   17, 26
Libya     [138]      17, 17P, 19
Malaysia             Malaysian Armed Forces[139]    17, 19, 34
Malaysian Maritime Enforcement Agency[140]  19
Royal Malaysia Police[139]           17, 18, 19, 26, 34
Royal Malaysian Custom[141]     —
Mexico                Mexican navy[100]          —
Monaco              Compagnie des Carabiniers du Prince[142][143]                17
Montenegro     Military of Montenegro[144]      17
Netherlands      Dutch police (about 250 Glock 17 pistols in use as a stopgap measure by the Arrestatieteam (Dutch SWAT))[145][146][147]  17
Military of the Netherlands[101][148][149]
The Royal Marechaussee Brigade Speciale Beveiligingsopdrachten (Special Protection Assignments Brigade) persoonsbeveiliging (PB), observatie team (OT) and sky marshals sections also use the Glock 26[150]     17, 18, 26
New Zealand    New Zealand Police[151] (an "unarmed service", but are trained to use firearms)             17
New Zealand Defence Force[152]            17
Niger    In use with Police and Garde Présidentielle[153]               17
Norway               Norwegian Armed Forces[100][101]        17 (as P-80, P-80NM1, and P-80NM2)
Papua New Guinea        [109]      17
Pakistan              Special Services Group[154]        17, 19
Philippines         National Bureau of Investigation[100]    —
National Intelligence Coordinating Agency[100] —
Philippine Drug Enforcement Agency[100]           —
Philippine National Police[100]   17 Gen 4
Presidential Security Group[100]              17
Philippine Marine Corps Marine Special Operations Group (MARSOG)[155]          21
Poland Border Guard[156]          19
Military Gendarmerie[101]          17
Polish police[157]             19
Portugal              Portuguese Marine Corps[101][158]       17
Public Security Police[158]           19
Republican National Guard[158]                19
Romania             Romanian Armed Forces[101]    17, 17L
Russia  Ministry of Internal Affairs (MVD), special forces[159][160]          17, 19
Federal Security Service (FSB)[161]          17
Special Operations Forces (Russia)[162] 17, 26
Saudi Arabia      Saudi Arabian Army[citation needed]     17
General Security[citation needed]           19
Serbia  Police of Serbia[163][164]            17, 19, 21, 35
Sierra Leone      Sierra Leone Police[165]               17
Singapore           Singapore Prison Service[166]    19
Special Task Squadron (STS) of the Police Coast Guard[167]         19
South Korea      [109]      17
Spain    Unidad Especial de Intervención (UEI) group of the Spanish Civil Guard[168]        17
Sweden              Swedish Armed Forces[101][169][170]   17 (as Pistol 88), 19 (as Pistol 88B)
  Switzerland      Police (Gendarmerie) Cantonal of Geneva[171] 19
Swiss Armed Forces: Swiss Grenadiers, ARD 10, FSK-17[172]        17, 26
Taiwan Various criminal investigation bureau outside major cities[173]  19
Thailand              National police (2,238 pistols)[100]           19
Timor Leste       National Police of East Timor[174]            19
Trinidad and Tobago      [109]      17
Ukraine               [109]      17
United Arab Emirates    [109]      17
United Kingdom              British Armed Forces[175]            17 (as L131A1),[176] 17T (as L132A1)
Police Service of Northern Ireland (PSNI)[177]   17
Scottish Police Specialist Firearms Units[178]       17
Specialist Firearms Command of the Metropolitan Police Service[179]    17, 26[180][181]
United States   Alaska State Troopers[182]          20, 22
Bureau of Alcohol, Tobacco, Firearms and Explosives[183]            22, 27
Drug Enforcement Administration[184] 19, 22, 23, 27
Federal Bureau of Investigation[185]      17, 19, 21, 22, 23, 26, 27
Florida Highway Patrol[186]         37
Homeland Security Investigations[187]  17, 19, 26
Internal Revenue Service – Criminal Investigation[188]  22, 23
Kentucky State Police SRT[189]  35, 27
Marine Corps Forces Special Operations Command[190]               19
United States Navy SEALs[191]  19
New York State Police[192]         37, 39
Oregon Department of Corrections[193]               22
Pennsylvania Game Commission[192]    31
United States Marshals Service[194]       17, 19, 22, 23
Ohio Department of Rehabilitation and Corrections[195]               19
Uruguay              Uruguayan National Army[196] 17
Venezuela         Venezuelan Armed Forces[100][101]      17
  Yemen Military of Yemen[197]  19