Q. [In regards to which parent has the right to name their child], what does the Halacha say?

A. Traditionally in Ashkenazi communities we do not follow the custom quoted in Ramban and Rabboseinu Baalei Hatossafoss and Teshuvos Maharam M’Rottenbourgh (mentioned in the prior question). Rather the prevalent minhag is to have the mother give the name of the first child and the father the second one. The mother will then name the third one and so on. (Otzar Habris p. 335). Keser Ephraim (39) mentions that maintaining the connection with her family is the reason why the mother is given first choice, since marriage tends to separate her from them. However there are those who do follow the first tradition (Leket Hayosher 107, Tashbatz 291). Some Sephardic communities uphold the tradition of the male names belonging to the father while the female ones to the mother. (Kuntres Vaikro Shmo B’Isroel)

Igrois Moshe (Y.D. 3: 97) in regards to a bris and naming done without the consent and presence of the father, rules that the mother also has a right to give a name as in the case of Binyomin (see prior question) and the name she gave although done unethically, would stay, as long as they mentioned who the real father is. The father has the right to add a name. Others disagree (Nachalas Yaakov, Shemos). See also in Likutey Sichos (7 p. 307) a comprehensive elucidation on rights of name giving.

Horav Shlomo Miller Shlit”a advises that one of the most important rules to follow in name giving is maintaining Sholom Bais, peace, harmony and affection, as the opposite endangers the child (Bris Avos 8: 23, Shmiras Hanefesh 99).

There may be other important factors involved in choosing a name, such as honoring a very dear departed benefactor etc. It is advisable to consult with a competent rabbinical authority, as to which is the correct course to follow.

Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit”a.