Penelitian ini bertujuan untuk memperoleh bukti empiris mengenai pengaruh intervensi self-affirmation dan gratitude berdasarkan pendekatan positive psychologi terhadap happiness mahasiswa akuntansi. Oxford Happiness Questionnaire (OHQ) digunakan untuk mengukur happiness. Desain penelitian yang digunakan adalah desain quasi-experiment dengan pretest dan post-test dalam studi eksperimental berbasis online. Kegiatan menulis reflektif tentang self-affirmation dan gratitude diadakan sebagai aktivitas intervensi. Peserta sejumlah 112 mahasiswa dibagi menjadi dua kelompok treatment dan satu kelompok kontrol, dengan jumlah akhir 11 peserta mengikuti penelitian. Data eksperimen dianalisis berdasarkan uji related paired sample t-test dan one-way ANOVA. Hasil penelitian menunjukkan intervensi self-affirmation dan gratitude secara statistis berpengaruh signifikan terhadap happiness, dengan tingkat happiness pada kelompok intervensi self-affirmation dan gratitude yang lebih tinggi dibandikan dengan kelompok kontrol. This study aimed to obtain empirical evidence regarding the effect of self-affirmation and gratitude intervention, based on the positive psychology approach, on the happiness of accounting students. Oxford Happiness Questionnaire was implemented to measure happiness. The research design utilized is quasi-experiment with pretest and post-test in an online-based experimental study. Reflective writing activities on self-interest and gratitude were held as the interventions. The 112 participants were divided into two treatments and one control group, with the final 112 participants joining the study. The experimental data were analyzed based on the related paired sample t-test testing and one-way ANOVA. The results showed the self-affirmation and gratitude intervention statistically significantly affected happiness, with happiness in the self-affirmation and gratitude higher than in the control group.