The name "Gampaha" in Sinhala literally means Five Villages.The five villages are known to be Ihalagama, Pahalagama, Medagama, Pattiyagama and Aluthgama. However, at present village Pattiyagama cannot be identified within the city limits of Gampaha and remains disputed. Gampaha was also known to be called Henarathgoda in the past.
As stated by archived documents, before the year 1815, Gampaha was a dense forest. The 5th governor of Ceylon, Sir Edward Barnes �made a visit to Gampaha in 1825, in his visit to observe the construction work of Colombo-Kandy road. The British colonists built Henarathgoda railway station in 1864 which act as a key factor for the progress and recognition of the town. In year 1867, the first rubber tree of Sri Lanka was planted in Henarathgoda botanical garden, nearby Gampaha.
Gampaha is renowned for the Ayurveda and indigenous medicine practice by late "Ayurveda Chakravarthi" Pundit Gabriel Perera Wickramarachchi.