This study aimed to examine the effectiveness of multimodal media based on Interactive Flat Panel (IFP) in improving elementary school students’ critical thinking skills in mathematics learning. The study employed a classroom action research (CAR) design using a mixed qualitative–quantitative approach conducted in two cycles, consisting of planning, action, observation, and reflection stages. The participants were 30 second-grade students of SDN Singopuran 03. Data were collected through critical thinking tests, observations, and documentation. The assessment of critical thinking skills referred to Facione’s indicators, including interpretation, analysis, evaluation, inference, and explanation. Quantitative data were analyzed descriptively through mean scores and learning mastery percentages, while qualitative data were analyzed from classroom observations and reflective notes. The findings revealed a significant improvement in students’ critical thinking skills after the implementation of multimodal media based on IFP. The average critical thinking score increased from 65.60 in Cycle I to 80.28 in Cycle II, with an overall improvement of 14.68 points. Learning mastery also increased from 60.00% in Cycle I to 86.67% in Cycle II. In addition, students’ learning activities improved from the “fair” category to the “good” category, particularly in questioning, discussion participation, expressing opinions, and problem-solving abilities. The most notable improvements were found in the analysis and explanation indicators, indicating that students became more capable of analyzing mathematical problems and communicating logical reasoning systematically. The study concludes that multimodal media based on Interactive Flat Panel (IFP) effectively enhances students’ critical thinking skills and learning engagement in elementary mathematics learning. The integration of visual, symbolic, contextual, and interactive representations creates a richer learning experience that supports the development of higher-order thinking skills in 21st-century education.