The donations were made by the Department of Disease Control, the Public Health Ministry, Government Pharmaceutical Organisation, Thai Red Cross Society, Somdet Phra Nyanasamvara Somdet Phra Sangharaja Wat Bavoranives Vihara Foundation under the Royal Patronage and Wat Phra Ram 9 Karnchanapisek.
The Foreign Ministry also donated another 1.3 million baht worth of medical supplies to Sri Lanka.
The donations were received by Sri Lanka's Ambassador CA Chaminda I Colonne on behalf of his government.
Earlier, the Thai government and private agencies had provided support to Sri Lanka, with the Thai Parliament donating 700,000 baht and Siam City Cement donating 4 million baht worth of medical supplies and monetary assistance.
Other Thai public and private sectors are also considering providing additional assistance to Sri Lanka.
"The donations reflect the close and cordial ties as well as the goodwill between Thai and Sri Lankan peoples," the announcement read.
"Moreover, the donation of humanitarian assistance to Sri Lanka is a reflection of Thainess as 'a true friend'."