Background: Recovery has become a priority in schizophrenia spectrum disorders (SSDs). This study aimed to investigate predictors of objective—general functioning and disability—and subjective—quality of life (QoL)—measures of functional outcomes in SSD. Methods: Sample: n = 77 SSD outpatients (age 18–64, IQ > 70) participating in a randomised controlled trial. Baseline data were used to build three multivariable linear regression models on: (i) general functioning—General Assessment of Functioning (GAF); (ii) disability—the World Health Organization Disability Assessment Schedule (WHODAS-2.0); and (iii) QoL—Satisfaction Life Domains Scale (SLDS). Results: Young age and being employed (R2 change = 0.211; p = 0.001), late adolescence premorbid adjustment (R2 change = 0.049; p = 0.0050), negative symptoms and disorganization (R2 change = 0.087; p = 0.025) and Theory of Mind (R2 change = 0.066, p = 0.053) predicted general functioning. Previous suicidal behaviour (R2 change = 0.068; p = 0.023) and negative and depressive symptoms (R2 change = 0.167; p = 0.001) were linked with disability. Previous suicidal behaviour (R2 change = 0.070, p = 0.026), depressive symptoms (R2 change = 0.157; p < 0.001) and illness recognition (R2 change = 0.046, p = 0.044) predicted QoL. Conclusions: Negative, disorganization and depressive symptoms, older age, unemployment, poor premorbid adjustment, previous suicide attempts and illness awareness appear to underlie a poor global functional outcome in SSD. Achieving recovery in SSD appears to require both symptomatic remission (e.g., through antipsychotics) and measures to improve mastery and relieve low mood.