Answer
Based on official Jordanian legal texts
No — the father is not, in principle, more entitled than the mother to custody under Jordanian law. Article 170 of the Personal Status Law makes the biological mother most entitled to custody and upbringing of her child, both during the marriage and after separation, then ranks those after her: the mother's mother (maternal grandmother), then the father's mother, then the father — so the father comes after them in the statutory order.
The reason for giving the mother priority is that she is usually best able to care for a young child in his early years; this is a presumption that can change if a custodian's condition under Article 171 fails in the mother, or harm to the child is established under Article 172, in which case custody passes to the next.
The mother's entitlement is therefore not absolute but limited by the child's best interest and the satisfaction of conditions; custody may pass to the father or another where the interest so requires.
Assessing who is most suitable for custody remains within the Sharia Court's competence on the facts of each case, and the outcome is not guaranteed for either party in advance.
This is a general explanation based on Jordanian Personal Status Law and does not replace advice from a qualified lawyer in a specific dispute.
