Obviously I hope this fails big time It's TRUE! Big Brother 19 will start September 28th, one week after BB18 ends, only on CBS All Access. Big Brother 19 will begin after the season-18 finale, which is slated for September 21. BB19 will run 10 weeks, slightly shorter than a normal season. It will be an expansion of the franchise and will not replace the annual summer season of Big Brother, which will continue to air on the CBS network in the USA & on Global in Canada. Julie Chen tweeted that she will be hosting BB19. Remember, you won't be able to watch BB19 without CBS All Access, so what are you waiting for, get your free trial started now!