Vacuum chambers having inflatable slit valve opening seals are described herein. In one example, a vacuum chamber includes a chamber body, a first inflatable seal, and a first slit valve door. The chamber body has a top, a bottom, and sidewalls. A first slit valve opening is formed in the sidewalls. The first inflatable seal is sealingly coupled to the sidewall and circumscribes the first slit valve opening. The first inflatable seal has a base coupled to the sidewall and a hollow tubular portion that can move laterally relative to the base. The first slit valve door is moveable between a close state that contacts the first inflatable seal to provide a vacuum seal between the first slit valve door and chamber body, and an open state that positions the first slit valve door clear of the first slit valve opening.