Kai Ludvig Jakob Knagenhjelm (28 August 1898 – 30 May 1987) was a Norwegian civil servant.
[1] On the maternal side he was a grandson of Jacob Thurmann Ihlen and Belgian citizen Ambrosine Pauline Rouquet.
[2] On the paternal side he was a nephew of Lord Chamberlain Jacob Roll Knagenhjelm.
The Knagenhjelm family had resided in Sogndal in recent times, and had been ennobled in 1721, then under the name Knagenhielm.
[1] He chaired Salomons Skofabrik and was a supervisory council member of Hafslund and Andresens Bank.