Nylander was born in Edefors, Sweden, the son of Emil Nyland, a physician, and his wife Hedvig von Post. He passed studentexamen in Växjö in 1920 and received a Candidate of Law degree from Uppsala University in 1925 and a bachelor's degree in 1928. Nylander was Head Marshal (Övermarskalk) at the university's 450th anniversary in 1927. 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 Berne in 1930 and as second secretary at the Foreign Ministry in Stockholm in 1933.
