The final round of the Miss Thailand competition, themed “The Ultimate Precious”, was held at Central Chaengwattana in Nonthaburi province.
Chonnikarn beat four other contenders and took home a bouquet, sceptre, sash, crown and a cheque for 800,000 baht.
She will be Thailand's representative at the Miss World pageant scheduled to be held in the United Arab Emirates in May.
Chonnikarn was followed by Marisa Phonthirat (Sakon Nakhon), Arabella Sitanan Gregory (Phatthalung), Kanokporn Payungwong (Ayutthaya) and Supansa Wattananusit (Amnat Charoen).
Chonnikarn graduated high school from The Prince Royal's College in Chiang Mai. She is studying in Chiang Mai University's Faculty of Pharmacy.
She speaks Thai and English, but also knows sign language and takes part in various types of Thai traditional dances.