Bo Lennart Georg Siegbahn (25 February 1915 – 7 January 2008) was a Swedish diplomat and politician.

[1] Siegbahn served in Stockholm City Court from 1937 to 1938 before joining Ministry for Foreign Affairs as an attaché in 1940.

[1] He was posted to Vichy in 1940, then to New York City in 1941, Washington, D.C. in 1943, and the Swedish Foreign Ministry in 1945 as second secretary.

[1] He was director (byråchef) at the Foreign Ministry from 1957 to 1962, counselor at the embassy in Rome from 1962 to 1963, and ambassador to Rabat and Dakar from 1963 to 1966 and to Tel Aviv from 1966 to 1970.

[1] Siegbahn was one of several people to be suspected as the author of a series of political satirical novels published under the pseudonym Bo Baldersson [sv; da; no; de].