With the proliferation of social media platforms like Instagram, Twitter, and Facebook, the dissemination of information has undergone a significant transformation. Instagram, distinguished by its emphasis on visual media, has emerged as a platform of choice for photo and video sharing. Despite its popularity, the platform's vast reach renders it vulnerable to malevolent activities, including cyberbullying. While prior research has employed SVM, NBC, C45, and K-Nearest Neighbors for cyberbullying analysis, these studies predominantly focused on Twitter. This paper presents a novel approach, harnessing the power of K-means Clustering to identify instances of cyberbullying on Instagram. In this study, a labelled dataset is gathered and subjected to pre-processing steps, including case folding, tokenization, removal of stopwords, normalization, and stemming. Subsequently, the K-means Clustering algorithm is implemented and evaluated using 10fold cross-validation. The results indicate a threshold value of 1.0, an accuracy rate of 64.25%, a precision of 79.29%, and a recall of 59.88% in categorizing bullying words on Instagram. This research underscores the potential of the K-means algorithm in effectively distinguishing between bullying and non-bullying comments. A notable advancement of this paper is the integration of the two tf-idf weighting methods with the K-means clustering algorithm, thereby enhancing the accuracy in grouping comment data into cyberbullying and non-cyberbullying categories.