Background/Objectives: This study aimed to develop and evaluate taste-masked theophylline pellets using hot-melt extrusion (HME) technology. Additionally, the study evaluates the efficacy of various taste-masking polymers by comparing three pH-dependent polymers, Kollicoat^® Smartseal 100P, Eudragit^® EPO, and Kollicoat^® MAE 100-55, in masking taste and optimizing drug release. Methods: Formulations were designed with varying drug loads (10%, 20%, and 30%) and plasticizer concentrations (20% and 30% PEG 1500). Lead formulations were characterized using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), bitter threshold level, and in vitro release testing. Stability was assessed under accelerated conditions (40 °C ± 2 °C and 75% ± 5% RH) for three months. Results: DSC confirmed homogenous dispersion of the drug within the polymer matrix. The optimized formulation comprising 20% theophylline, 20% PEG 1500, and 60% Kollicoat^® Smartseal 100P demonstrated effective taste masking, releasing only 1.1% of the drug in simulated salivary fluid (SSF) within two minutes, significantly lower than the pure drug (29.5%, p < 0.05), Kollicoat^® MAE 100-55 (2.8%, p < 0.05), and comparable to Eudragit^® EPO (2.1%, p > 0.05). Solubility studies further confirmed that theophylline release from the lead formulations remained well below its reported bitter threshold, which could prevent taste perception and mitigate bitterness. In gastric fluid, complete drug release was achieved from Kollicoat^® Smartseal 100P and Eudragit^® EPO, while Kollicoat^® MAE 100-55 exhibited limited release. Stability studies showed that the Kollicoat^® Smartseal 100P formulation maintained its texture, taste-masking efficacy, and dissolution profile under accelerated conditions. Conclusions: The study demonstrates the novel exploration of Kollicoat^® Smartseal 100P for HME application, and its effectiveness in achieving robust taste masking for theophylline, improving patient compliance, particularly in pediatric and geriatric populations.