Diplomats — reference index 12
- Robert Bacon
- Robert Birch — Australia
- Robert Cotton — Australia
- Robert H. Tiscornia — Argentina
- Robert Lansing
- Robert Liston — United Kingdom
- Robert Peet Skinner
- Robert Smith
- Roberto Abdenur — Brazil
- Roberto Alemann — Argentina
- Roberto Dañino — Peru
- Roberto de Oliveira Campos — Brazil
- Roberto E. Dalton — Argentina
- Roberto Gaja — Italy
- Roberto Guillermo MacLean Ugarteche — Peru
- Roberto Lazzeri Montaño — Mexico
- Roberto V. Pesqueira — Mexico
- Rodolfo García Arias — Argentina
- Rodrigo de Saavedra y Vinent, Marquis of Villalobar — Spain
- Roelf Petrus Meyer — South Africa
- Roelof Frederik “Pik” Botha — South Africa
- Roesmin Nurjadin — Indonesia
- Rolf Ekéus — Sweden
- Rolf Friedemann Pauls — Germany
- Rolf Sieber — Germany
- Ron Dermer — Israel
- Ronald Ian Campbell — United Kingdom
- Ronald Reagan
- Ronen Sen — India
- Rosan Perkasa Roeslani — Indonesia
- Roth — France
- Rómulo Sebastián Naón — Argentina
- Rubens Antonio Barbosa — Brazil
- Rubens Ricupero — Brazil
- Rutherford B. Hayes
- Rüstem Efendi — Türkiye
- Ryohei Murata — Japan
- Ryozo Kato — Japan
- Ryūichi Kuki — Japan
- Ryūji Takeuchi — Japan
- S. Jaishankar — India
- S. R. Nathan — Singapore
- S. S. Ray — India
- Saburō Takagi — Japan
- Sadao Iguchi — Japan
- Sadao Saburi — Japan
- Saddam Hussein
- Saeed Ahmad Ghobash — UAE
- Saeed Al-Shamsi — UAE
- Sahabzada Yaqub Khan — Pakistan
- Said Shihab Ahmad — Iraq
- Salim Yusuf Mansoor — Iraq
- Sallai Meridor — Israel
- Salvador de Madariaga — Spain
- Salvador Furtado de Mendonça Drummond — Brazil
- Sameh Shoukry — Egypt
- Samir Sumaidaie — Iraq
- Samuel Assefa — Ethiopia
- Samuel de Souza Leão Gracie — Brazil
- Santiago Cabanas Ansorena — Spain
- Santosh Jha — India
- Saqr Ghobash — UAE
- Saverio Fava — Italy
- Sedat Önal — Türkiye
- Seifoullah Yousry Pasha — Egypt
- Seiya Nishida — Japan
- Seleshi Bekele — Ethiopia
- Seo Gwang-beom — Korea
- Serdar Kılıç — Türkiye
- Sergey Kislyak — Russia
- Sergio Fenoaltea — Italy
- Sergio Vento — Italy
- Sergiy Korsunsky — Ukraine
- Sergiy Kulyk — Ukraine
- Sesostris Sidarouss Pasha — Egypt
- Setsuzō Sawada — Japan
- Severin Lorich — Sweden
- Seyfettin Bey — Türkiye
- Sérgio Amaral — Brazil
- Sérgio Corrêa da Costa — Brazil
- Sérgio Teixeira de Macedo — Brazil
- Shavkat Khamrakulov — Uzbekistan
- Sheila Sisulu — South Africa
- Shen Tung — China
- Sherry Rehman — Pakistan
- Shigeo Yamada — Japan
- Shinsuke J. Sugiyama — Japan
- Shin’ichirō Kurino — Japan
- Shunji Yanai — Japan
- Shūzō Aoki — Japan
- Silvino Gurgel do Amaral — Brazil
- Simcha Dinitz — Israel
- Sin Tae-mu — Korea
- Sir Antony Acland — United Kingdom
- Sir Auckland Geddes — United Kingdom
- Sir Cecil Spring Rice — United Kingdom
- Sir Christian Turner KCMG — United Kingdom
- Sir Christopher Meyer — United Kingdom
- Sir David Manning — United Kingdom
- Sir Edward Thornton — United Kingdom