Karl Lennart Hjalmar Nylander (4 September 1901 – 15 July 1966) was a Swedish diplomat.

[2] Nylander became an attaché at the Ministry for Foreign Affairs in Stockholm in 1928 and served at the Swedish Consulate General in New York City the same year.

Nylander then served as an attaché in Bern in 1930 and as second secretary at the Foreign Ministry in Stockholm in 1933.

In 1942, Nylander was posted in Berlin as trade counsellor, and in 1944 he was appointed legation secretary there.

He served 10 years as consul general before being appointed envoy at the Swedish Embassy in Mexico City in 1955.