Jebb ya zama Jakadan Birtaniya a Majalisar Dinkin Duniya daga 1950 zuwa 1954 kuma zuwa Paris daga 1954 zuwa 1960. Shi ne wakilin dindindin na farko na Birtaniya a Majalisar Dinkin Duniya. A cikin wannan matsayi na karshe ya yi fushi da cewa tattaunawar sirri tsakanin Birtaniya, Faransa da Isra'ila kafin mamayewar Suez a 1956 ya faru a Sèvres ba tare da saninsa ba, kuma, a wasu hanyoyi, Firayim Minista Harold Macmillan ya yi watsi da shi a taron "babban iko" na Paris a 1960.
Jakadan Burtaniya a Majalisar Dinkin Duniya