Diplomatic relation: the arrangement between two countries by which each has representatives in the other country. (Definition of “diplomatic relations” from the Cambridge Advanced Learner’s Dictionary & Thesaurus © Cambridge University Press).
Nepal has diplomatic relations with following countries on following dates

S. No.  Country Date Since Remarks
1 United Kingdom 1816 AD  Has embassy of Nepal
2 USA 25 April 1947  Has embassy of Nepal / Has consulate general at New York
3 India 13 June 1947  Has embassy of Nepal / Has consulate general at Kolkata
4 France 20 April 1949  Has embassy of Nepal
5 PR of China 01 August 1955  Has embassy of Nepal / Has consulate general at Hong Kong and Lhasa
6 Russian Federation 20 July 1956  Has embassy of Nepal
7 Japan 01 September 1956  Has embassy of Nepal
8 Sri Lanka 01 July 1957  Has embassy of Nepal
9 Egypt 16 July 1957  Has embassy of Nepal
10 FR of Germany 04 April 1958  Has embassy of Nepal
11 Austria 15 August 1959
12 Italy 31 August 1959
13 Serbia 07 October 1959
14 Switzerland 10 November 1959
15 Poland 25 November 1959
16 Malaysia 01 January 1960  Has embassy of Nepal
17 Philippines 12 February 1960
18 Australia 15 February 1960  Has embassy of Nepal
19 Myanmar (Burma) 19 March 1960  Has embassy of Nepal
20 Pakistan 20 March 1960  Has embassy of Nepal
21 Netherlands 02 April 1960
22 Laos 20 May 1960
23 Israel 01 June 1960  Has embassy of Nepal
24 Sweden 10 June 1960
25 Thailand 30 November 1960  Has embassy of Nepal
26 Indonesia 25 December 1960
27 Mongolia 05 January 1961
28 Hungary 15 January 1961
29 New Zealand May 1961
30 Afghanistan 01 July 1961
31 Argentina 01 January 1962
32 Chile 1962
33 Greece 02 February 1962
34 Turkey 15 November 1962
35 Lebanon 18 August 1963
36 Belgium 19 August 1963  Has embassy of Nepal
37 Iran 14 December 1964
38 Canada 18 January 1965  Has embassy of Nepal
39 Jordan 20 August 1965
40 Denmark 15 December 1967  Has embassy of Nepal
41 Bulgaria 15 April 1968
42 Romania 20 April 1968
43 Algeria 29 April 1968
44 Spain 13 May 1968
45 Iraq 30 October 1968
46 Singapore 25 March 1969
47 Sudan 11 July 1969
48 Syria 26 February 1970
49 Ethiopia 15 April 1971
50 Kuwait 25 February 1972  Has embassy of Nepal
51 Bangladesh 08 April 1972  Has embassy of Nepal
52 Albania 23 May 1972
53 Norway 26 January 1973
54 DPR of Korea 15 May 1974
55 Republic of Korea 15 May 1974  Has embassy of Nepal
56 Finland 21 September 1974
57 Tanzania 10 January 1975
58 Morocco 18 February 1975
59 Cuba 25 March 1975
60 Cambodia (Kampuchea) 18 April 1975
61 Vietnam 15 May 1975
62 Kenya 03 June 1975
63 Mexico 25 November 1975
64 Luxembourg 27 November 1975
65 Nigeria 20 December 1975
66 Libya 30 December 1975
67 Peru 28 January 1976
68 Brazil 07 February 1976  Has embassy of Nepal
69 Portugal 01 September 1976
70 Bahrain 13 January 1977  Has embassy of Nepal
71 Oman 21 January 1977  Has embassy of Nepal
72 Qatar 21 January 1977  Has embassy of Nepal
73 United Arab Emirates 22 January 1977  Has embassy of Nepal
74 Saudi Arabia 15 March 1977  Has embassy of Nepal / Has consulate general at Jeddah
75 Costa Rica 16 August 1977
76 Maldives 01 August 1980
77 Cyprus 18 August 1980
78 Mauritius 12 February 1981
79 Iceland 25 May 1981
80 Bhutan 03 June 1983
81 Holy See 10 September 1983
82 Malta 25 September 1983
83 Brunei 03 February 1984
84 Panama 15 February 1984
85 Tunisia 14 April 1984
86 Somalia 24 October 1984
87 Zimbabwe 27 November 1984
88 Gabon Republic 17 June 1985
89 Yemen 25 December 1985
90 Fiji 12 June 1986
91 Zambia 10 September 1986
92 Mozambique 30 September 1986
93 Nicaragua 05 October 1986
94 Venezuela 28 April 1987
95 Colombia 07 May 1987
96 Bolivia 21 May 1987
97 Estonia 20 April 1992
98 Latvia 20 April 1992
99 Ukraine 15 January 1993
100 Armenia 26 March 1993
101 Kyrgyzstan 26 March 1993
102 Belarus 19 July 1993
103 Moldova 20 July 1993
104 Czech Republic 02 March 1994
105 Slovak Republic 04 March 1994
106 Guyana 22 June 1994
107 South Africa 28 July 1994  Has embassy of Nepal
108 Azerbaijan 28 February 1995
109 Seychelles 10 October 1996
110 Slovenia 02 December 1997
111 Macedonia 06 January 1998
112 Croatia 06 February 1998
113 Ireland 19 August 1999
114 Bosnia and Herzegovina 12 January 2000
115 Lithuania 08 February 2005
116 San Marino 10 August 2005
117 Republic of Tajikistan 13 September 2005
118 Georgia 22 September 2005
119 Turkmenistan 17 October 2005
120 Ecuador 21 June 2006
121 Paraguay 02 August 2006
122 Guatemala 08 August 2006
123 Honduras 18 August 2006
124 Vanuatu 19 September 2006
125 Andorra 22 September 2006
126 Congo 22 September 2006
127 Haiti 23 May 2007
128 Saint Vincent and Grenadines 27 September 2007
129 Dominican Republic 28 September 2007
130 Botswana 08 January 2009
131 Mali 19 November 2009
132 Lesotho 18 May 2010
133 Montenegro 18 July 2011
134 Solomon Islands 15 December 2011
135 Uruguay 18 April 2012
136 Monaco 15 May 2012
137 Islamic Republic of Mauritania 04 December 2012
138 Tuvalu 11 December 2012
139 Independent State of Samoa 28 March 2013
140 Papua New Guinea 12 April 2013
141 Kazakhstan 30 June 2015
142 Jamaica 01 October 2015
143 Republic of Guinea 12 May 2016
144 El Salvador 21 September 2016
145 Uganda 12 June 2017
146 Côte d’Ivoire 16 June 2017
147 Republic of Djibouti 14 July 2017
148 Antigua and Barbuda 25 July 2017
149 Cabo Verde 03 August 2017
150 Liberia 17 August 2017
151 Niger 21 September 2017
152  Eritrea  31 October 2017
153  Bahamas  7 November 2017
154 Liechtenstein 22 November 2017
155  Angola  9 December 2017
156 Burkina Faso 29 December 2017
157 Benin 23 January 2018
158 Uzbekistan 26 January 2018