Nikolaj first appears in the U.S. registration record in 2001. Its popularity climbed over the following decades. In 2019, 19 babies received the name (ranked #5101). Today it sits well outside the top 1,000 (around #7635), with roughly 12 babies named Nikolaj each year. Nikolaj's usage has held roughly steady recently. In total, around 154 babies have been registered with this name since 1880.