AI technologies are steadily gaining ground across multiple sectors, drawing both enthusiasm and concern—especially in the field of education. The recent advent of AI tools designed to assist student learning has drawn serious attention from educators and learners. The classroom implications of AI tools are ushering in new possibilities that could radically transform conventional teaching methods. In learning English as a second language, AI tools have shown noteworthy efficacy, particularly in supporting writing skills. A significant body of research has already been carried out to assess the feasibility and effectiveness of AI tools in supporting English language learners. This review-based research paper aims to synthesize existing literature on the implications of AI tools in enhancing English writing skills. Most of the existing studies are limited by small sample sizes; therefore, this review integrates their findings to offer a broader and more comprehensive perspective. Analyzing the reviewed papers, this study seeks to address the following key inquiries: 1. What are the features of AI tools that have been proven effective in enhancing ESL writing? 2. What are the potential drawbacks of using AI in ESL writing that educators should be aware of? 3. How might AI influence the traditional, teacher-aided ESL writing classroom? Through a qualitative narrative review of relevant research, this study evaluates the application of AI in ESL writing. It seeks to provide a more comprehensive insight into the viability of AI, its limitations, and its potential for further development.