This review presents a comprehensive evaluation of the effectiveness of routinely delivered psychological therapies across inpatient, outpatient and University-based clinics. This was a pre-registered systematic-review of studies meeting pre-specified inclusion criteria (CRD42020175235). Eligible studies were searched in three databases: MEDLINE, CINAHL and PsycInfo. Pre-post treatment (uncontrolled) effect sizes were calculated and pooled using random effects meta-analysis to generate effectiveness benchmarks. Moderator analyses were used to examine sources of heterogeneity in effect sizes. Overall, 252 studies (k = 298 samples) were identified, of which 223 (k = 263 samples) provided sufficient data for inclusion in meta-analysis. Results showed large pre-post treatment effects for depression [d = 0.96, (CI 0.88-1.04), p [less than or equal to] 0.001, k = 122], anxiety [d = 0.8 (CI 0.71-0.9), p [less than or equal to] 0.001, k = 69], and other outcomes [d = 1.01 (CI 0.93-1.09), p [less than or equal to] 0.001, k = 158]. This review provides support for the effectiveness of routinely delivered psychological therapy. Effectiveness benchmarks are supplied to support service evaluations across multiple settings.