In this study, we investigated the effect of Biochanin A (BioA), an O‐methylated isoflavone on the brown‐fat phenotype formation and on the associated thermogenic program including mitochondrial biogenesis and lipolysis in C3H10T1/2 MSCs. Our data demonstrates that Treatment with BioA in an adipogenic differentiation cocktail induced formation of brown‐fat–like adipocytes from C3H10T1/2 MSCs without treatment with a known browning inducer (rosiglitazone or T3) at an early stage of differentiation. The formation of brown‐fat–like adipocytes by BioA treatment was evidenced by upregulation of key thermogenic markers:Ucp1,Pgc1α,Prdm16, andPparγ. BioA also increased the expression of beige (Cd137andFgf21) and brown (Elovl3andZic1)‐specific markers. Additionally, BioA treatment promoted mitochondrial biogenesis, judging by the upregulation of genes;Cox8b,Cidea,Dio2,Sirt1,Opa1, andFis1. BioA treatment increased the amount of mitochondrial DNA and its encoded proteins: oxidative phosphorylation complexes (I–V); this change was associated with high oxygen consumption by C3H10T1/2 MSCs. A small‐interfering‐RNA–induced gene knockdown and experiments with dorsomorphin‐driven competitive inhibition revealed that BioA exerts the thermogenic action via activation of AMPK signaling. Our study shows the mechanism of BioA‐induced promotion of a brown‐fat phenotype. Nonetheless, clinical research is necessary to validate BioA as a brown‐fat‐like signature inducer.