Highway 103 is an east-west highway in Nova Scotia that runs from Halifax to Yarmouth.

The highway follows a route of 291 kilometres (181 mi) along the province's South Shore region fronting the Atlantic coast. The route parallels its predecessor, local Trunk 3. The highway varies from 2-lane controlled access to 2-lane local secondary roads on the section between Yarmouth and Hebbville. East of Hebbville to Hubbards, the highway is 2-lane controlled access, with the exception of a 3 km (2 mi) 4-lane divided freeway near Chester. From just west of Hubbards (exit 6), to the interchange with Highway 102 (near Bayers Lake) in Halifax, the highway is 4-lane divided freeway. Same as Highway 101, kilometre markers increase running west-to-east, increasing from Yarmouth to Halifax; with exit numbers running east-to-west, increasing from Halifax to Yarmouth.

In 2013, Highway 103 was redesignated as the Fishermen's Memorial Highway.

The highway has developed sporadically since the 1970s, with the 2-lane controlled access portion to Bridgewater being largely responsible for the abandonment of CN Rail's South Shore line, the former Halifax and Southwestern Railway.

In November 1998, construction was completed that twinned a five kilometer section of highway between exit 2 and exit 3. In November 2006, construction was completed that twinned 15 kilometres of highway between exit 3 and exit 5. In December 2006, an 8.3 kilometre bypass around Barrington was completed.

In late September 2015 a new section of highway was opened to bypass the Port Joli area. In November 2016, a new section was completed which bypassed Port Mouton. Residents complained that the single exit east of the community had lengthened the trip for people heading west from Port Mouton.

The new interchange in Ingramport (exit 5A) opened in January 2017.

Work on twinning Highway 103 from exit 5 (Tantallon) to exit 5A (Ingramport) began in February, 2018 and was completed in December, 2020. Twinning from exit 5A (Ingramport) to exit 6 (Hubbards) started in 2020 and was completed in July of 2024. Construction on the twinning from exit 6 (Hubbards) to exit 7 (East River) is underway.

• Fishermen's Memorial Highway - June 2013
• Barrington Bypass - Barrington to Oak Park, Shelburne County
• Nine Mile Road - Sable River to Jordan Falls, Shelburne County

Between 2006 and 2009, there were 29 deaths on the highway. In 2009, it was considered Nova Scotia's deadliest highway and was ranked the second most dangerous highway in Canada by the Canadian Automobile Association. In 2009 alone, ten people died in automobile accidents on the highway, according to the Nova Scotia Department of Transportation and Infrastructure Renewal. Between 2008 and 2012, there were 22 fatalities on the highway.

In September 2018, local residents raised concern over the presence of a road sign on the highway, near the turnoff to Port Mouton, that had a very confusing appearance, looking like a patchwork of several other road signs. It was supposedly revealed when a hotel removed its billboard advertisement, revealing the sign below.

County	Location	km	mi	Exit	Destinations	Notes
Halifax	Halifax	0.0	0.0	1B	Hwy 102 to Hwy 101 – Halifax, Dartmouth, Windsor, Airport, Truro, Bedford	Hwy 103 eastern terminus.
		0.4	0.25	1D	Dunbrack Street	Eastbound exit only.
		1.2	0.75	2	Trunk 3 west (St. Margarets Bay Road) to Route 333 (Lighthouse Route) – Beechville, Lakeside, Peggys Cove	Westbound signed as exits 2A (west) and 2B (east)
	Timberlea	5.6	3.5	3	To Trunk 3 / Timberlea Village Parkway
	Hubley	12.7	7.9	4	Trunk 3 – Timberlea, Five Island Lake
	Upper Tantallon	19.6	12.2	5	Route 213 (Hammond's Plains Road) to Trunk 3 / Route 333 – Peggys Cove, Bedford
	​	29.9	18.6	5A	To Trunk 3 – Ingramport, Black Point, Boutiliers Point
Lunenburg	Hubbards	40.8	25.4	6	Trunk 3 / Route 329 – Queensland, Blandford
	East River	50.0	31.1	7	Trunk 3 / Route 329 – Chester, Blandford
	Chester	57.2	35.5	8	Trunk 14 – Chester, Windsor
	Chester Basin	61.3	38.1	9	Trunk 12 – Kentville, New Ross
	Mahone Bay	75.0	46.6	10	Trunk 3 – Lunenburg, Martin's River
	Blockhouse	79.9	49.6	11	Route 324 (Cornwall Road) to Route 325 – Mahone Bay, Lunenburg
	Bridgewater	91.6	56.9	12	Trunk 10 to Route 331 / Route 332 – West LaHave, East LaHave, Riverport
		91.8	57.0	Crosses the LaHave River
		93.0	57.8	12A	Bridgewater Business Park	New roundabout interchange opened on December 20, 2024
		94.8	58.9	13	Route 325 (Victoria Road) to Route 331 – Bakers Settlement, Wileville
	Hebb's Cross	101.4	63.0	14	Trunk 3 east – Hebbville, Bridgewater	At-grade
	Italy Cross	107.9	67.0	15	Italy Cross Road − Crousetown, Petite Riviere, Broad Cove, Rissers Beach Provincial Park	At-grade
	Middlewood	111.7	69.4	16	Hirtle Road / Camperdown School Road − Vogler's Cove, Broad Cove, Camperdown	At-grade
Queens	​	122.4	76.1	17	Route 331 – East Port Medway, Voglers Cove, Charleston, Cherry Hill	At-grade
				Crosses the Medway River
		124.2	77.2	17A	Port Medway Road − Mill Village, Port Medway, East/West Berlin, Charleston	At-grade
		130.5	81.1	18	Trunk 3 west – Brooklyn, Liverpool	At-grade
	Liverpool	136.9	85.1	19	Trunk 8 to Trunk 3 – Milton, Brooklyn
		137.5	85.4	Crosses the Mersey River
	​	140.3	87.2	20A	To Trunk 3 (Old Port Mouton Road) – White Point, Hunt's Point	At-grade
		153.2	95.2	21	To Trunk 3 – Summerville Centre, Hunt's Point, White Point	At-grade
	Port Mouton	155.9	96.9		Trunk 3 east	Intersection closed, use exit 21
	​	160.7	99.9	22	Trunk 3 west – Port Joli, East Side Port l'Hébert, Kejimkujik National Park (Seaside Adjunct)	At-grade; Trunk 3 is unsigned
		163.3	101.5		Trunk 3 east – Port Joli	Intersection closed, use exit 22
Shelburne	Sable River	176.6	109.7	23	Trunk 3 west – Lockeport	At-grade
	Jordan Falls	190.3	118.2	24	Trunk 3 east / Lake John Road – Lockeport	At-grade
		190.8	118.6		Jordan Branch Road − Jordan Branch, Jordan Ferry, Jordan Bay	At-grade
	​	196.0	121.8	25	Trunk 3 west – Shelburne	At-grade
	Shelburne	200.0	124.3	26	Route 203 – Ohio, East Kemptville	At-grade
	Birchtown	206.9	128.6	27	Trunk 3 east – Gunning Cove, Ingomar	At-grade
	Clyde River	220.3	136.9	28	Route 309 south (South Road) / Quinns Falls Road – Port Clyde, Eel Bay, Port La Tour	At-grade
	Barrington	230.0	142.9	29	Trunk 3 west to Route 309 – Port La Tour	At-grade
	Riverhead	234.3	145.6	30	To Trunk 3 – Barrington Passage, Lower Woods Harbour, Upper Woods Harbour
Yarmouth	Pubnico	256.0	159.1	31	To Trunk 3 / Route 335 – Lower Argyle	At-grade
	Argyle	268.4	166.8	32	Trunk 3 east – Central Argyle, Argyle Head	East end of Trunk 3 unsigned concurrency; at-grade, proposed interchange
		269.0	167.1	Crosses the Argyle River
		269.4	167.4	32A	Trunk 3 west – Glenwood	West end of Trunk 3 unsigned concurrency; at-grade, proposed intersection closure
	​	276.2	171.6		Eel Lake Road / Belleville Road	At-grade
		276.8– 277.4	172.0– 172.4	Crosses Eel Lake
	Tusket	281.2	174.7	33	Route 308 to Trunk 3 – Quinan
		282.4	175.5	Crosses the Tusket River
	Yarmouth	291.3	181.0		Hardscratch Road − Brooklyn	Hwy 103 western terminus
		292.1	181.5		Trunk 3 (Starrs Road) to Hwy 101 / Trunk 1 – Ferry
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Closed/former       Concurrency terminus       Incomplete access       Unopened

• Halifax
• Beechville
• Lakeside
• Timberlea
• Hubley
• Lewis Lake
• Upper Tantallon
• Head of St. Margarets Bay
• Ingramport
• Black Point
• Queensland
• Hubbards
• Simms Settlement
• East River
• East Chester
• Windsor Road
• Chester Basin
• Beech Hill
• Gold River
• Western Shore
• Martins Point
• Martins River
• Oakland
• Clearland
• Blockhouse
• Maitland
• Pine Grove
• Oakhill
• Bridgewater
• Cookville
• Bridgewater
• Wileville
• Hebbville
• Hebbs Cross
• Italy Cross
• Middlewood
• Danesville
• Mill Village
• Brooklyn
• Milton

• Highway 103 Improvement Projects