Olof Wilhelm Robert Sahlberg (* Stockholm, 29 March 1837 - †  Stockholm, 6 July 1922) was a Swedish chess composer.

He composed direct chess problems in two, three and more moves. His greatest success was the first prize in the chess problem competition of the 5th American Chess Congress (New York, 1880). It has a great keymove: 1.Bc2-d1!! with Zugzwangposition.

The tournament, considered the championship of the United States, was won by George Mackenzie.

He published much of his work in the magazines Tidskrift för Schack and Nordiske Skakproblemer.

He wrote the book ‘Schackgropen’ i La Croix's café i bazaren å Norrbro: några gamla minnen ur Stockholms forna schacklif (Stockholm, 1903).