An electrical connector with a solder ball locking structure includes a base, solder balls and terminals. The base has terminal slots, solder ball slots under the terminal slots, and channels respectively communicating the terminal slots with the solder ball slots. The solder balls are respectively disposed in the solder ball slots. Each ball has a bottom end projecting over a bottom of the base. The terminals are respectively disposed in the terminal slots. Each terminal has a contact extending toward a top of the terminal slot and at least one connecting sheet extending toward a bottom of the terminal slot. The connecting sheet extends to the solder ball slot through the channel and intrudes into the solder ball to form a locking structure, which prevents the solder ball from falling out of the solder ball slot.