Katechaki or Katehaki Avenue (Greek: Λεωφόρος Κατεχάκη Leoforos Katechaki) is one of Athens and its suburbs' main roads in the metropolitan area and the prefecture. Its total length is approximately 12 to 13 km.
The avenue begins by an interchange with the Mesogeiou Avenue which was constructed in the 1970s, the avenue forms an intersection with the road to Zografou and Olaf Palme Street and north to Papagou. By the avenue with a stretch of 2 km features industrial buildings, shops and office complexes constructed between the 1970s and the 1990s. Since 2004, it has an interchange with the Attiki Odos with two lanes of exits and 300 m north, its first toll station. The avenue enters the Hymettus' forest filled with pine, spruce, fir (Greek Fir) and cypress trees. It later enters an interchange with the University of Athens and a road to the top of the mountain along with communications tower which is not used during the nighttime hours. The avenue ends by Karea Avenue.
The avenue serves as the bypass of Athens connecting traffic from its northern, the western, the eastern and the southern suburbs along with Vouliagmenis Avenue.
The avenue was under construction in the late-1950s and first opened in the 1960s. Traffic lights were installed later on and an interchange with the Mesogeiou Avenue was added later. Between 2001 and 2004, its interchange with the ring was under construction and opened later. It was used on July 2004 for the bus that carried players of the Greece national football team from the city's airport down to Kallimarmaro for its celebration of the victory and its claim to the Euro 2004 title after beating Portugal, fans were alongside the avenue in large numbers.