Mother Jewish, father not:[1] A child born from a gentile father is to be circumcised.

Father Jewish, mother not:[2] A child whose mother is not Jewish is not to be circumcised, just as we rule regarding a non-Jewish child, as explained in Halacha 9.

[1] See Pischeiy Teshuvah Yoreh Deah 266:14

[2] Michaber Yoreh Deah 266:13