Purpose: Although smoking cessation reduces the risk of all-cause mortality, evidence-based cessation treatments are underused. This study examined healthcare provider knowledge of evidence-based cessation treatments and associations between knowledge and clinical practice characteristics. Design: Cross-sectional survey. Setting: 2020 DocStyles. Subjects: 1480 U.S. healthcare providers. Measures: Provider knowledge of availability of tobacco use disorder diagnostic criteria, clinical practice guideline availability, treatment efficacy, evidence-based counseling modalities, and medications approved by the U.S. Food and Drug Administration (FDA). Analysis: Adjusted odds ratios (aORs), adjusted for personal and clinical practice characteristics. Results: Less than half of respondents demonstrated high knowledge of availability of diagnostic criteria (36.8%), cessation treatment efficacy (33.2%), evidence-based counseling modalities (5.6%), and FDA-approved medications (40.1%). Significant differences were found between specialties: compared to internists, family physicians were less likely to have low knowledge of medications (aOR =.69, 95% CI =.53,.90) and obstetricians/gynecologists were more likely to have low knowledge of medications (aOR = 2.62, 95% CI = 1.82, 3.76). Overall, few associations between knowledge and clinical practice characteristics were identified. Conclusion: Most providers had low knowledge of the topics of interest, with little variation across clinical practice characteristics, indicating room for improvement. Efforts to improve provider knowledge of evidence-based treatments are an important component of a comprehensive approach to improving delivery and use of cessation interventions and increasing tobacco cessation.