Adolescence is the second period of rapid growth that may serve as a window of opportunity for compensating for early childhood growth failure. It is considered as a nutritionally critical period of life with the increased physical growth and development requiring increased nutrient requirements. Global burdens of poor nutrition in adolescents include micronutrient deficiencies, underweight, and overweight/obesity. In the Philippines, adolescents face nutrition problems from poor dietary intake. Nutritional status of adolescents is affected by nutrition knowledge and dietary habits. Hence, this study aimed to assess the relationship among nutrition knowledge, dietary habits, and nutritional status of senior high school students at Florentino Torres High School, Tondo, Manila. This cross-sectional quantitative study involved 181 respondents which were obtained through simple random sampling. Data were gathered through online self-administered questionnaires. Normality of the data was tested through Shapiro-Wilk normality test and Spearman Rank correlation was used with level of significance (p) at 0.05 to test correlation. The results showed that most respondents had normal nutritional status based on BMI index. However, there is a high magnitude/severity of underweight of 35% prevalence. Moreover, majority had satisfactory level of nutrition knowledge. Majority of the respondents had moderate intake of unhealthy diet and low intake of healthy diet. The most common unhealthy food groups consumed were white rice, white pasta, and fine-ground oats, sweets, and white bread/bakery products. Whereas the most common healthy food groups consumed were vegetables, white meat (chicken), and milk. The results of the study revealed that there was a very weak negative monotonic but not significant relationship between nutritional status and nutritional knowledge (p = 0.447); pro-healthy diet index and nutrition knowledge (p = 0.355); and non-healthy diet index and nutrition knowledge (p = 0.372). Meanwhile, there was a very weak positive monotonic but not significant relationship between pro-healthy diet index and nutritional status (p = 0.359), and non-healthy diet index and nutritional status (p = 0.249). In conclusion, there was no significant relationship among nutrition knowledge, nutritional status, and dietary habits of senior high school students in Florentino Torres High School, Tondo, Manila. Further studies in different localities are recommended in looking at the relationship of nutrition knowledge, dietary habits, and nutritional status.