Fusarium oxysporum merupakan penyebab penyakit layu fusarium yang dapat menurunkan produksi tomat. Pengendalian hayati dengan menggunakan bakteri antagonis seperti Bacillus sp. merupakan alternatif pengendalian yang potensial dan ramah lingkungan.  Penelitian bertujuan untuk mengetahui kemampuan Bacillus sp. dalam mengendalikan penyakit layu fusarium pada tanaman tomat di lapangan. Percobaan menggunakan rancangan acak kelompok dengan 5 perlakuan dan 5 ulangan, meliputi: kontrol, Bacillus sp. B42, Bacillus sp. B64, gabungan Bacillus sp. B42 dan B64, serta fungisida. Hasil pengujian menunjukkan bahwa Bacillus sp. B.64 merupakan bakteri antagonis terbaik dalam menekan intensitas penyakit  layu fusarium, karena dapat menunda masa inkubasi 15,76%, menekan intensitas penyakit 38,77%, meningkatkan kandungan fenol tanaman (tanin, saponin dan glikosida), serta meningkatkan pertumbuhan dan hasil tanaman dengan meningkatkan bobot kering tajuk 32,05%, bobot kering akar 15,23%, dan bobot buah per tanaman 46,48%. ABSTRACT Fusarium oxysporum is the causal agent of fusarium wilt disease which decreases the production of tomatoes. Biological control managenement using bacterial antagonists is a potential alternative to prevent the infection of the disease. The aim of this research was to determine the ability of Bacillus sp. to control tomato fusarium wilt in the field. Randomized block design (RBD) experiment was used consisting of 5 treatments and 5 replications i.e. control, Bacillus sp. B42, Bacillus sp. B64, combination of Bacillus sp B42 + B64, and fungicide. The results showed that Bacillus sp. B64 was the best bacterial antagonist agent to control tomato wilt disease by delaying incubation period (15.76%), decreasing disease intensity (38.77%), increasing phenol compounds (tannin, saponin, glycosides) and improving plant growth and yield. Furthermore, the results showed the increasement of shoot dry weight to 32.05%, root dry weight to 15.23%, and yield to 46.48% as well.