Aber-erch ([abɛrˈɛrχ], Welsh for "Mouth of the Erch") is a small village and former civil parish on the Llŷn Peninsula in the Welsh county of Gwynedd. The village lies approximately 1 mile (1.6 km) east of Pwllheli. A river, the Afon Erch runs through the village.

The parish was abolished in 1934 and incorporated into that of Llannor, now the community of Llannor. It is a mostly Welsh-speaking village and its name is often truncated to "Berch" [bɛrχ] in the local Welsh dialect.

There is a primary school, playschool, and a railway station. The Church of St Cawrdaf is a grade I listed building.

Aber-erch has a beach called 'Traeth Glan y Don' (which roughly translates to 'Shore of the wave beach') which extends from Morfa'r Garreg, Pwllheli to Pen-ychain. Parking for the beach is near the railway station. From the beach you have a view of Harlech Castle in the east all the way down to Tywyn (on a clearer day even further south) and to the west Pwllheli and the St Tudwal's Islands. Access to the beach is through a footpath next the caravan and camp-site. This beach is ideal for days when the wind is from the north or north west due to the sheltered bay.

The ward includes the village of Y Ffor and the small settlement of Penrhos.

• John Elias (1774-1841), a powerful Christian preacher: "as if talking fire down from heaven"
• Ellis Owen Ellis (1813-1861), a Welsh portrait painter, cartoonist and illustrator.