The Sieve is a river in Italy. It is a tributary of the Arno, into which it flows at Pontassieve after a course of 62 km. The Sieve rises in the Tuscan-Emilian Apennines, near the Futa Pass, at 930 m of elevation.

Sieve
Location
Country	Italy
Physical characteristics
Source
• location	near Futa Pass, Apennines, Italy
• elevation	777 m (2,549 ft)[1]
Mouth
• location	Arno
• coordinates	43°46′13″N 11°26′28″E / 43.7703°N 11.4412°E / 43.7703; 11.4412
Length	58 km (36 mi)[1]
Basin size	840 km2 (320 sq mi)[1]
Basin features
Progression	Arno→ Tyrrhenian Sea

The territory in which it flows is known in Italian as Valdisieve. In Italian language, the name "Sieve" is feminine, and is therefore referred to as La Sieve.