Mananchaya Sawangkaew (Thai: มนัญชญา สว่างแก้ว; born 10 July 2002) is a tennis player from Thailand.
She has a career-high singles ranking of 247 by the Women's Tennis Association (WTA), achieved on 4 December 2023. Sawangkaew has won two singles titles and one doubles title on the ITF Women's Circuit.
On the ITF Junior Circuit, she achieved a career-high combined ranking of 14, on 28 January 2019. She reached the quarterfinals of the girls' singles draw at the 2019 Australian Open.
Sawangkaew made her debut for Thailand Fed Cup team in 2019.