Forests offer provisioning, regulating, cultural, and supporting ecosystem services, and sustaining these services is becoming increasingly important. Forest certification programs serve as a viable market-based mechanism for enhancing sustainable forest management and achieving broader sustainability goals. However, certification cost has consistently been identified as a substantial barrier to enrollment in forest certification, especially for small non-industrial private forest (NIPF) landowners. We explored NIPF landowners’ willingness-to-pay (WTP) for adopting forest certification and compared it with certification cost. Using a state-wide landowner survey, we estimated average WTP for certifying forestland in Arkansas, USA. We also employed Tobit regression to explore factors that influence the WTP. We found that the average WTP for certification was US$12.10/property, considerably lower than average certification cost (US$75/property). However, among respondents who had a non-zero WTP, the average WTP was US$57.60/property. Moreover, we found that landowners WTP was positively related with gender, income, length of land tenure, intention of family legacy, interest in adopting forest certification, motivations for timber production and recreation, and price premium benefits; whereas it was negatively correlated with hunting and farming motivations and beliefs about expanded markets and increased paperwork. While targeting the landowners with attributes that influence WTP may help increase the certification enrollment of NIPF landowners, the broader success of forest certification entails reaching out to the majority proportion of NIPF landowners who are not yet willing to pay for certification programs. In addition to better connecting with NIPF landowners, bridging the gap between the WTP for certification and certification cost, for example, via providing joint certification for multiple landowners and incentive programs (e.g., tax reductions, cost sharing), is essential to expand NIPF landowners’ participation in forest certification.