Robert Hjalmar Nobel (/noʊˈbɛl/; Swedish: [nʊˈbɛl]; August 4, 1829 – August 7, 1896) was the oldest son of Immanuel Nobel and his wife Caroline Andrietta Ahlsell, brother of Ludvig and Alfred Nobel.
He was working for his brother Ludvig when he bought an interest in an oil refinery in Baku, Azerbaijan in 1876. He and his brother started Branobel, which was an important early oil company that controlled a large amount of Russian output.