Otoyol 3 (English: Motorway 3), also known as the European Motorway (Turkish: Avrupa Otoyolu) and abbreviated as the O-3 is a 245.1 km (152.3 mi) long otoyol in East Thrace, Turkey. The O-3 runs from Edirne to Istanbul and is the only motorway in Turkey located entirely in Europe. The motorway begins west of Edirne at "Edirne Batı K1" junction with the D.100 where it then continues as a beltway passing just north of Edirne. From there, the motorway passes through mostly rural farmland until it enters the Istanbul metropolis near Silivri. The eastern end of O-3 ends at the Istanbul Bağcılar "Mahmutbey Batı K20" Junction.^[1]

O-3 "Avrupa otoyolu" "Mahmutbey Batı K19" junction connects to O-7, E80, Istanbul Airport and Yavuz Sultan Selim Bridge in the north direction, to Ataturk Airport with the 2nd Beltway in the south direction. The last junction of the European motorway "Mahmutbey Doğu K20" connects to O-2 motorway (2nd Beltway) and Fatih Sultan Mehmet Bridge in the east direction, to 1st Beltway (O-1) with the O3-O1 connection road in the south direction.^[2] The motorway has six lanes, three in each direction, except for a 44.6 km (27.7 mi) section between Silivri and Esenyurt.

Province	District	km	mi	Exit[3]	Destination	Notes
Edirne	Edirne Merkez	0	0	K1	D.100 connector Edirne Batı junction	E80 route
		11.5	7.1	K2	D.535 connector Lalapaşa junctionn	E80 route
		15.8	9.8	K3	D.100 connector Edirne Doğu junction	E80 route
		16.7	10.3	Edirne Toll Plaza
	Havsa	35.7	22.1	K4	D.020 connector Havsa junction	E80 route
Kırklareli	Babaeski	62.9	39	K5	D.555 connector Babaeski junction	E80 route
	Lüleburgaz	87.3	54.2	K6	D.565 connector Lüleburgaz junction	E80 route
Tekirdağ	Saray	116.1	72.1	K7	P.59-01 — Vakıflar [tr], connector Saray junction	E80 route
	Çorlu	136.3	84.6	K8	P.59-04 —Velimeşe connector Çorlu junction	E80 route
Istanbul	Silivri	154.8	96.1	K9	D.567 connector Çerkezköy junction	E80 route
		167.1	103.8	K10	Northbound O-7- E80—Kınalı junction Southbound E84	connector to D.100 and D.110
		174.3	108.3	K11	Silivri D100 connector—Silivri junction
		186.1	115.6	K12	Ortaköy connector — Selimpaşa junction
	Büyükçekmece	193.6	120.2	K13	Kumburgaz connector — Kumburgaz junction
		199.6	124	K14	D.569 — Çatalca junction
	Esenyurt	211.7	131.5	K15	P.34-84 — Hadımköy junction
		216.6	134.3	K16	Esenyurt connector — Esenyurt junction
	Avcılar	217.7	135.0	K17	Avcılar-H.dere connector — Avcılar junction
		220.2	136.2	K18	Nakkaş-Başakşehir connector — Isparta Kule junction
	Başakşehir Küçükçekmece	228.0	141.3		Mahmutbey Toll Plaza
		229.1	142.0	K19	Northbound O-7 and E80 route, Southbound Bakırköy connector Mahmutbey Doğu junction	connector to the YSS Bridge and E80 route
	Bağcılar	231.8	146.4	K20	east end of O-3 Mahmutbey Batı junction	connector to the O-2(istanbul second Bltwy) and Fatih Sultan Mehmet Bridge
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Incomplete access        Tolled

• List of motorways in Turkey

• Turkish General Directorate of Highways. Turkey motorway map. 2024.
• Turkish General Directorate of Highways İstanbul motorway map. 2024.