Quebec Route 343

{{Short description|Highway in Quebec}}

{{Use Canadian English|date=January 2023}}

{{Infobox road

|province=QC

|type=QC

|route=343

|maint=Transports Québec

|map=Route 343-QC.png

|established=

|decommissioned=

|alternate_name=

|length_km =74.4

|length_round =1

|length_ref=Ministère des transports, "Distances routières", page 99, Les Publications du Québec, 2005

|direction_a=North

|direction_b=South

|terminus_a={{jct|state=QC|QC|347}} in Saint-Côme

|terminus_b={{jct|state=QC|QC|138}} in Saint-Sulpice

|previous_type=QC

|previous_route=342

|next_type=QC

|next_route=344

|cities=L'Assomption, Joliette

|junction= {{jct|state=QC|QC|158}} in Joliette
{{jct|state=QC|A|40}} in L'Assomption

|}}

Route 343 is a provincial highway located in the Lanaudière region of Quebec. It runs from Route 138 west of Saint-Sulpice and south of Autoroute 40 and ends at the junction of Route 347 east of Saint-Come and north of Saint-Alphonse-Rodriguez where it has a concurrency with Route 337.