The study aims to examine the effect of innovation as a moderating factor for the effectiveness of diversification strategies on the sustainability of hospitality firms in Nigeria. The study applied a quantitative method involving a survey design. A questionnaire measurement instrument was constructed and deployed on a sample of 104 respondents from 3 four-star hotels in the study area. Confirmatory Factor Analysis (CFA) was used to validate the constructs in the measurement instrument. Multiple regression analysis was used to test the study hypotheses. The results showed that concentric and conglomerate diversification strategies have a significant positive effect on the sustainability of hospitality firms. Also, innovation has a significant positive moderating effect on the relationship between diversification strategies and the sustainability of hospitality firms. Therefore, the study concluded that hospitality firms, particularly hotels should consistently innovate and diversify their services and product to gain market share, customer patronage and improve organizational performance in the long run while also remaining sustainable.