Background: The current literature lacks an updated review examining return to play (RTP) and return to prior performance (RTPP) after shoulder surgery in professional baseball players. Purpose: To summarize the RTP rate, RTPP rate, and baseball-specific performance metrics among professional baseball players who underwent shoulder surgery. Study Design: Systematic review; Level of evidence, 4. Methods: A literature search was performed utilizing the PubMed, MEDLINE, and CINAHL databases and according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria were English-language studies reporting on postoperative RTP and/or RTPP in professional baseball players who underwent shoulder surgery between 1976 and 2016. RTP rates, RTPP rates, and baseball-specific performance metrics were extracted from qualifying studies. A total of 2034 articles were identified after the initial search. Meta-analysis was performed where applicable, yielding weighted averages of RTP and RTPP rates and comparisons between pitchers and nonpitchers for each type of surgery. Baseball-specific performance metrics were reported as a narrative summary. Results: Overall, 26 studies featuring 1228 professional baseball players were included. Patient-level outcome data were available for 529 players. Surgical interventions included rotator cuff debridement (n = 197), rotator cuff repair (RCR; n = 43), superior labrum from anterior to posterior repair (n = 124), labral repair (n = 103), latissimus dorsi/teres major (LD/TM) repair (n = 21), biceps tenodesis (n = 17), coracoclavicular ligament reconstruction (n = 15), anterior capsular repair (n = 5), and scapulothoracic bursectomy (n = 4). Rotator cuff debridement was the most common surgical procedure, while scapulothoracic bursectomy was the least common (37.2% and 0.8% of interventions, respectively). Meta-analysis revealed that the RTP rate was highest for LD/TM repair (84.5%) and lowest for RCR (53.5%), while the RTPP rate was highest for LD/TM repair (100.0%) and lowest for RCR (27.9%). RTP and RTPP rates were generally higher for position players than for pitchers. Nonvolume performance metrics were unaffected by shoulder surgery, while volume statistics decreased or remained similar. Conclusion: RTP and RTPP rates among professional baseball players were modest after most types of shoulder surgery. Among surgical procedures commonly performed on professional baseball players, RTP and RTPP rates were highest for LD/TM repair and lowest for RCR.