Objectives: To explore the relationship between small intestinal bacterial overgrowth (SIBO) and laryngopharyngeal reflux (LPR). Methods: Data from patients undergoing high resolution manometry, pH-impedance monitoring, and hydrogen methane breath testing at a single tertiary center were analyzed retrospectively. SIBO was determined by a ≥ 20 ppm rise in breath hydrogen from baseline within 90 minutes after ingestion of lactulose. Patients were grouped by SIBO result and compared for subjective LPR symptoms on the Reflux Symptom Index (RSI) in addition to objective manometric and reflux parameters, including mean nocturnal baseline impedance (MNBI) in the proximal and distal esophagus. Results: Forty-one patients were analyzed, of which 46.3% were positive for SIBO. Patients with SIBO had a significantly greater LPR symptom burden on RSI (26.5 ± 9.3 vs. 16.9 ± 8.9, P = 0.002). Independently, SIBO was associated with throat clearing (P = 0.016), cough (P < 0.001) and globus (P = 0.003). Objectively, there was no difference in manometric or reflux parameters except patients with SIBO had significantly lower MNBI in the proximal esophagus (1970.2 ± 511.6 Ω vs. 2504.2 ± 816.1 Ω, P = 0.026). Conclusion: Patients with SIBO have greater LPR symptom severity and impaired mucosal integrity in the proximal esophagus. Future study should look to determine if treating SIBO improves symptoms of LPR.