The present invention provides a fishing spinning reel in which functional degradation of a spool reciprocating device is avoided while reducing the size of a reel unit. The fishing spinning reel (100) includes a reel unit (1) and a rotor (2) rotatably supported by the reel unit (1). The reel unit (1) includes: a body (10) having a side opening portion (13) and in which a spool reciprocating device (70) is housed and supported; a lid (30) closing the side opening portion (13); and a cover member (40) mounted on a rear portion of the body (10). A handle shaft (5) is rotatably supported by the body (10) and the lid (30). In the rear portion of the body, a rear opening portion (15) for receiving at least a part of a component of the spool reciprocating device (70) and disposing the component on the rear side is formed. The cover member (40) covers the rear opening portion (15) and the component.