ABSTRAK: Umbi bit (Beta vulgaris L.) terbukti memiliki aktivitas antioksidan sehingga dapat digunakan dalam sediaan yang diaplikasikan pada kulit untuk menangkal radikal bebas. Pemanfaatan ekstrak umbi bit diharapkan menghasilkan sabun transparan guna memberi pelindungan kulit dari radikal bebas. Penelitian ini mengkaji pengaruh penambahan ekstrak umbi bit terhadap aktivitas antioksidan dan kualitas sabun padat transparan. Perlakuan yang diberikan adalah variasi penambahan ekstrak umbi bit, antara lain UP1 (0 ml), UP2 (2,5 ml), UP3 (5 ml), UP4 (7,5 ml), dan UP5 (10 ml) dalam formulasi sabun transparan. Penambahan ekstrak umbi bit secara signifikan mempengaruhi aktivitas antioksidan, kadar air, asam lemak bebas, tingkat keasaman (pH), stabilitas busa, serta karakteristik sensori sabun transparan. Perlakuan UP5 merupakan perlakuan terbaik dengan aktivitas antioksidan 95,58 ppm, kadar air 16,00%, asam lemak bebas 0,43%, pH 9,87, stabilitas busa 79,74%, dan uji eritema 0,05 (hampir tidak nampak). Penilaian secara deskriptif terhadap sabun transparan menunjukan bahwa sabun berwarna cokelat, agak beraroma umbi bit, dan tekstur agak lembut.Kata kunci: antioksidan, ekstrak umbi bit, sabun transparan ABSTRACT: Beetroot (Beta vulgaris L.) has been shown to have antioxidant activity; therefore, it can be added in a preparation applicated to the skin against free radicals. The use of beetroot extract is expected to produce a transparent soap that can protect the skin from free radicals. This research aimed to study the effect of beetroot extract on antioxidant activity and the quality of transparent solid soap. The treatments which given were the addition of beetroot extract volume, namely UP1 (0 ml), UP2 (2.5 ml), UP3 (5 ml), UP4 (7.5 ml), and UP5 (10 ml) in the formulation of transparent soap. The research showed that the addition of beetroot extract significantly affected antioxidant activity, moisture content, free fatty acid, degree of acidity (pH), foam stability, and sensory characteristics of the transparent soap. The UP5 treatment was the best treatment with 95.58 ppm antioxidant activity, 16.00% moisture content, 0.43% free fatty acid, 9.87 pH, 79.74% foam stability, and 0.05 erythema test (almost invisible). The result of the descriptive test on the transparent soap showed that the soap had a brown color, a rather beetroot aroma, and a rather soft texture.