Background: The unprecedented access to information in the 21st century entails a deep understanding of information and communication technology (ICT)-related factors in education and their impacts on learning and teaching. The role of attitudes towards ICT is a proven factor in student achievement. However, there is no consensus about the direction of this impact. Objectives: This study aimed to explore the relationship between student attitudes towards ICT including interest in ICT (INTICT), perceived ICT competence (COMPICT), perceived autonomy related to ICT use (AUTICT) and ICT in social interaction (SOIAICT), and their achievement scores for mathematics, reading, and science by analysing student-, school-, and country-level factors hierarchically in the quartiles of performance. Methods: The study group was determined as 300,279 15-year-old students from 21,903 schools in 53 countries. Descriptive and correlational analyses were carried out in addition to the hierarchical linear modelling (HLM) employed to reveal the relationship between attitudes towards ICT and academic achievement in mathematics, reading, and science through the investigation of student-, school-, and country-level factors hierarchically in the quartiles of performance. Results and Conclusions: The results detected moderate to weak relationships among the constructs of INTICT, COMPICT, AUTICT and SOIAICT. Based on the HLM findings, complex interactions between ICT attitudes and academic performance were identified with a tendency towards positive associations between specific attitude components and high achievement levels, particularly in mathematics and science. The research identified the significance of considering student-, school-, and country-level factors for high, above-average, below-average, and low achievers to comprehensively understand the role of ICT attitudes in shaping educational outcomes. Takeaways: Policymakers should design educational policies, subject-specific strategies and ICT-related interventions by considering the multifaceted factors influencing student performance across different subjects and achievement quartiles. Particularly at the school and country levels, contextual factors should be evaluated when designing interventions to support low achievers.