The disclosure relates to a sofa armrest. The sofa armrest includes a main body made by blow molding, the upper end of the inner side surface of the main body is recessed inward to form a fabric mounting groove for mounting armrest fabric, and the lower end of the inner side surface of the main body is provided with clamping-connection grooves for being connected with connectors of a sofa underframe. The sofa armrest is made by a blow molding process, and compared with traditional solid sofa armrests, the sofa armrest has the advantages of low weight, high production speed and less manufacturing materials; when the armrest fabric is squeezed and deformed, debris accumulates on the lower wall of the fabric mounting groove or on a seat cover fabric, cleaning of dust and debris is facilitated, and the overall hygiene of a sofa is maintained.