Eero Erik Nikolai Järnefelt (1863 - 1937) was a Finnish realist painter.

Eero Järnefelt was born in Viipuri, Finland. His father Alexander Järnefelt was an officer in the Russian army and his mother was Elisabeth Clodt von Jürgensburg. He studied at the St. Petersburg art academy between 1883 and 1885, the same one Albert Edelfelt had studied at.

He went to study in Paris in 1886 where he became friends with Akseli Gallen-Kallela, Emil Wikström and Louis Sparre . He was inspired by the plein-air and naturalistic paintings by Jules Bastien-Lepage

On a trip to Keuruu in 1889 he met actress Saimi Swan . They were married in 1890.

His most famous painting is probably The Wage Slaves (Raatajat rahanalaiset) from 1893.