Mananchaya Sawangkaew (Thai: มนัญชญา สว่างแก้ว; born 10 July 2002) is a tennis player from Thailand.

On the ITF Junior Circuit, she achieved a career-high combined ranking of No.

[1][5] Sawangkaew made her WTA main draw debut at the 2024 Thailand Open 2 in Hua Hin, after qualifying[6][7] but lost to eventual champion Rebecca Šramková.

[12] In the second round Sawangkaew overcame third seed Yuan Yue to become the first Thai player to reach a WTA Tour quarterfinal since Luksika Kumkhum in Hong Kong in 2018.

[16] At the next and last 2024 Asian swing tournament, the Jiangxi Open, Sawangkaew qualified for the main draw and recorded wins over seventh seed Lucia Bronzetti,[17] and then Zheng Saisai against whom she saved two match points, to reach back-to-back quarterfinals.