The Kağıthane-Piyalepaşa Tunnel (Turkish: Kağıthane-Piyalepaşa Tüneli) is a twin-tube road tunnel under the inner city of Istanbul, Turkey connecting the Kağıthane district and Piyalepaşa Boulevard in Beyoğlu district. Opened in 2009, it is 3,186 m (10,453 ft) long.
The tunnel is part of a project of the Istanbul Metropolitan Municipality to build seven tunnels for the "City of Seven Hills", which is the nickname of Istanbul. It was opened on March 14, 2009 as the first tunnel of this project after a construction time of four years. Its southeast entry is situated on the Piyalepaşa Boulevard, which runs between the neighborhoods Okmeydanı and Kasımpaşa. The northwest entry is located in Kağıhane. The two independent tubes with two lanes each are 11.80 m (38.7 ft) wide, 7.33 m (24.0 ft) high and 3,180 m (1.98 mi) long.