BADASS (Bayesian AGN Decomposition Analysis for SDSS Spectra) decomposes Sloan Digital Sky Survey (SDSS) spectra and fits Type 1 ("broad line") Active Galactic Nuclei (AGN) in the optical. The fitting process uses the Bayesian affine-invariant Markov-Chain Monte Carlo sampler emcee (ascl:1303.002) for robust parameter and uncertainty estimation, as well as autocorrelation analysis to access parameter chain convergence. Out of the box, BADASS fits SDSS spectra, and MANGA IFU cube data; the code can be modified to fit user-input spectra of any instrument.