Proposed is a slim-type LED lighting apparatus with integrated junction box and LED module. The apparatus includes: the junction box having a plurality of first cable inlets that allow circular cables or conduits to be introduced thereinto and are arranged on a circumference of a side surface of a cylindrical body with an open upper side and a recessed lower side, an upper opening into which a wiring cover is coupled to be selectively openable and closable for wiring work, and a lower recess having a first flange protruding from the cylindrical body; the LED module inserted through the lower recess of the junction box and then integrally coupled to a lower surface of the junction box in face-to-face contact therewith; and a plurality of interchangeable trims of different diameters selectively coupled to a lower portion of the junction box and configured to be interchangeable with each other.