Dmytro Stepanovich Bortniansky (Ukrainian: Дмитро Степанович Бортнянський, or Dmitry Bortnyansky, 1751–1825) was a Ukrainian-Russian composer who was particularly popular at the court of Emperor Paul.

He was born in Hlukhiv, Ukraine on October 28, 1751. At the age of seven he was sent to sing with the Imperial Chapel Choir in St. Petersburg, then the capital of the Russian Empire. While in St. Petersburg he studied under Italian master Baldassare Galuppi, who was the director of the Imperial Chapel Choir from 1765–1768. In 1769, Bortniansky followed Galuppi to Italy to work in opera. While in Italy, he had considerable successes; operas he composed there, and had performed, included Creonte (Venice, 1776); Quinto Fabio (Modena, 1778); and Alcide (Venice, 1778).

Bortniansky returned to St. Petersburg in 1779 and in 1796 was the first native of the Russian empire to be appointed Director of the Imperial Chapel Choir. While in St. Petersburg he composed at least four more operas (in French). He also composed liturgical music for the Russian Orthodox Church, combining the styles of Eastern and Western European sacred music, mostly in a polyphonic style he learned in Italy; some of these works are polychoral as well, using a style descended from the Venetian polychoral technique of the Gabrielis. In all, he wrote over 100 anthems, sacred concertos, cantatas, hymns and Ave Marias, and these works are central to 18th century Russian sacred music. Bortniansky also composed chamber music and piano sonatas.

Bortniansky spoke Ukrainian, Russian, Italian, French, and German. In 1882, Tchaikovsky edited the liturgical works of Bortniansky, which were published in ten volumes. He died in St. Petersburg on October 10, 1825 and is interred at Alexander Nevsky Monastery in St. Petersburg.