Based on PISA 2022 data, as many as 82% of participating countries, including Indonesia, experienced a decline in mathematics competency scores. In Indonesia, around 71% of students do not achieve minimum competency in mathematics, and 81.67% of elementary school students have below-average mathematical problem-solving abilities. One of the factors that hinders student learning achievement is boredom. Previous research has shown that creating a new and interactive learning environment can reduce boredom. Therefore, this study aims to identify the effectiveness of indoor and outdoor learning environments on elementary school students' academic achievement in mathematics. This study uses an experimental quantitative design with a two-group matched independent measure approach to compare the two learning environments, namely indoor and outdoor environments. The results showed no significant difference between indoor and outdoor learning environments on students' academic achievement. Statistical analysis produced a t value of 0.307 and a Sig value (2-tailed) of 0.760 (p> 0.05), which means that both learning environments have the same effect on students' academic achievement in mathematics. These findings indicate that the learning environment, both indoor and outdoor, does not significantly affect elementary school students' learning outcomes in mathematics. AbstrakBerdasarkan data PISA 2022, sebanyak 82% negara peserta, termasuk Indonesia, mengalami penurunan skor kompetensi matematika. Di Indonesia, sekitar 71% siswa tidak mencapai kompetensi minimum dalam matematika, dan 81,67%, siswa SD memiliki kemampuan pemecahan masalah matematis di bawah rata-rata. Salah satu faktor yang menghambat capaian belajar siswa adalah kebosanan. Penelitian sebelumnya menunjukkan bahwa menciptakan lingkungan belajar baru dan interaktif dapat mengurangi kebosanan. Oleh karena itu penelitian ini bertujuan untuk mengidentifikasi efektivitas lingkungan belajar indoor dan outdoor terhadap capaian akademik matematika siswa SD. Penelitian ini menggunakan desain kuantitatif eksperimental dengan pendekatan two-group matched independent measure untuk membandingkan antara lingkungan indoor dan outdoor. Hasil penelitian menunjukkan tidak ada perbedaan signifikan antara lingkungan belajar indoor dan outdoor terhadap capaian akademik siswa. Analisis statistik menghasilkan nilai t sebesar 0.307 dan nilai Sig (2-tailed) sebesar 0.760 (p > 0.05), yang berarti kedua lingkungan belajar memiliki efek yang sama terhadap capaian akademik matematika siswa. Temuan ini mengindikasikan bahwa lingkungan belajar, baik indoor maupun outdoor tidak secara signifikan mempengaruhi hasil belajar siswa SD dalam mata pelajaran matematika.