An easy, low-cost, and highly selective carbon paste electrode based on an ion-imprinted polymer (IIP) to determine Pb(II) in real samples was developed. The recognition cavities based on a cross-linked polymer selective to Pb(II) were created using vinyl pyridine. The modified CPE was constructed by a composite mixture with the synthesized IIP. A notable difference was observed in the electrochemical response of the electrodes modified with the IIP and a non-imprinted polymer, demonstrating the unique properties of the IIP recognition sites. The parameters related to the current intensity were optimized; the selectivity was also studied considering potential interference ions. The proposed modified electrode demonstrated to be as (or more) selective to Pb(II) compared to others previously reported in the literature. A linear concentration range from 3.3 mg/L to 33 mg/L with a limit detection of 1 mg/L was obtained. The Pb(II) preconcentrated on the electrode surface was successfully quantified in real potable water samples without previous treatment.