Slottsbacken (Swedish: [ˈslɔ̂tːsˌbakːɛn], "Castle Slope") is a street in Gamla stan, the old town in central Stockholm, Sweden.
It stretches east from the Stockholm Cathedral and the Royal Palace down to the street Skeppsbron which passes along the eastern waterfront of the old town. In the western end, the alley Källargränd leads south to the square Stortorget, while Storkyrkobrinken extends Slottsbacken west beyond the cathedral and Högvaktsterrassen, down to the square Riddarhustorget. On the southern side of Slottsbacken, three alleys connect to the interior throng of the old town: On either side of the Tessin Palace are Finska Kyrkogränd and Bollhusgränd, while Österlånggatan begins in the low-lying eastern part of the slope.