Bukit Mertajam is the capital of Central Seberang Perai, Penang, Malaysia. It is commonly known as BM among its locals. It is located nearby Kulim, Kedah.

The town of Bukit Mertajam is named after the nearby hill with the highest peak at 547m above sea level. The hill is named after the Mertajam tree (Lepisanthes rubiginosa).

It is located in Central Seberang Perai, in the state of Penang, with Butterworth to the northeast, Kubang Semang to the north, Simpang Ampat to the south and Kulim to the east, and Penang island to the west. The town is located about 9km to the east of the coastline and about 336km north of Kuala Lumpur.

Bukit Mertajam is administered by the Seberang Perai Municipal Council (Majlis Perbandaran Seberang Perai or MPSP in Malay). MPSP is one of the few municipal councils in Malaysia which administers more than one district. MPSP administers all three districts of the mainland Penang (also known as Province Wellesley). The districts are North, Central and South Seberang Perai.