MISTTBORN can simultaneously fit multiple types of data within an MCMC framework. It handles photometric transit/eclipse, radial velocity, Doppler tomographic, or individual line profile data, for an arbitrary number of datasets in an arbitrary number of photometric bands for an arbitrary number of planets and allows the use of Gaussian process regression to handle correlated noise in photometric or Doppler tomographic data. The code can include dilution due to a nearby unresolved star in the transit fits, and an additional line component due to another star or scattered sun/moonlight in Doppler tomographic or line profile fits. It can also be used for eclipsing binary fits, including a secondary eclipse and radial velocities for both stars. MISTTBORN produces diagnostic plots showing the data and best-fit models and the associated code MISTTBORNPLOTTER produces publication-quality plots and tables.