Modular filtration system

The present disclosure relates to modular filtration systems using removable filter cassettes for filtering liquids including, for example, liquids used in semiconductor manufacturing. A filtration system may include a removable filter cassette having a filter inlet port and a filter outlet port, a filter cassette holder configured to receive and retain the filter cassette, and a main assembly. The main assembly can further comprise a filter inlet interface port configured to receive the filter inlet port, and a filter outlet interface port configured to receive the filter outlet port and can define flow paths to direct flow to and from the filter cassette. The filter cassette holder may be movably coupled to the main assembly such that the filter cassette is movable relative to the main assembly from an unmated position to a mated position.