Ayer Rajah is a residential neighbourhood within the downtown core of George Town in the Malaysian state of Penang.

This leafy, affluent neighbourhood, situated adjacent to the Penang Botanic Gardens, mostly consists of landed properties such as bungalows and semi-detached houses, surrounded by tree-lined avenues.

[2][3] By 1796, 10 years after the establishment of George Town by Francis Light, more than 2,000 acres (8,100,000 m2) of the area had been cleared, forming the Ayer Rajah Estate.

[4] Other prominent personalities who once resided within this neighbourhood include the first Malaysian Prime Minister, Tunku Abdul Rahman, and local DAP politician-cum-lawyer, Karpal Singh.

[1] Rapid Penang bus route 10 includes a handful of stops along Gottlieb Road.