Sarlahi 1 is one of four parliamentary constituencies of Sarlahi District in Nepal.

This constituency came into existence on the Constituency Delimitation Commission (CDC) report submitted on 31 August 2017.

[1]Sarlahi 1 incorporates Chandranagar Rural Municipality, wards 1–14 of Ishwarpur Municipality, wards 1,2 and 7 of Kabilasi Municipality, wards 2–9 of Haripur Municipality and [[Lalbandi|Lalbandi Municipality It encompasses the following Province No.

2 Provincial Assembly segment