Count Semyon Romanovich Vorontsov (June 26, 1744 - July 9, 1832) was a Russian diplomat from the noble Vorontsov family. Among his siblings were Alexander Vorontsov, Elizabeth Vorontsova, and Catherine Vorontsova-Dashkova.

For the last 47 years of his life, starting in 1785 until his death in 1832, he lived in Great Britain. During this period, he served as the ambassador of Russia: first in the Kingdom of Great Britain from 1785 to 1800, and then in the United Kingdom from 1801 to 1806.

In 2002, a memorial plaque was unveiled on Woronzow Road, named in his honor, created by architect V. Bukhaev. This event took place in memory of his assistance to the poor living in the area.