The principle of the best interests of the child, guaranteed by Article 24(2) of the Charter of Fundamental Rights, must be complied with when drafting and interpreting rules on jurisdiction in European family law. Although the EU legislator has essentially fulfilled its obligations under Article 24(2), further legislative improvements to strengthen the best interests of the child in jurisdiction law are still possible. Regarding the interpretation of the Brussels IIb Regulation and the Maintenance Regulation, the case law of the ECJ is not consistent. Although the Court regularly refers to the best interests of the child, its reasoning often remains one-dimensional. In fact, the significance of the principle depends on the regulatory context: the best interests of the child in matters of parental responsibility differ from those in maintenance law. Thus, the best interests of the child within the meaning of the Maintenance Regulation tend to reinforce the general objective of the Regulation, which is to protect the maintenance creditor. The situation is more complex in the jurisdiction system of the Brussels IIb Regulation. The various general grounds for jurisdiction, e.g., jurisdiction at the child's habitual residence, are based on certain ideas about where conducting proceedings typically serves the interests of the child. If these general rules do not optimally reflect the individual situation, the agreement and transfer of jurisdiction allow for responding to the individual case. Both the standardised and case-specific rules on jurisdiction are based on overarching elements of the broad concept of the best interests of the child. These elements must guide the interpretation of the Brussels IIb Regulation.