Metro… In Dino is an urban drama revolving around four couples residing in metropolitan cities who are primarily dealing with their respective relationships and complexities. Monty (Pankaj Tripathi) and Kajol (Konkona Sen Sharma) are a middle-aged married couple residing in Mumbai who have been married for nearly two decades, and have differences that often result in arguments. Monty’s colleague suggests he have an extramarital affair, which would reignite the spark in his marriage. Monty’s plan ends in a disaster with Kajol catching him red-handed. Kajol’s mother, Shivani (Neena Gupta), lives in Pune with her husband, Sanjeev (Saswata Chatterjee), whose marriage has hit rock bottom. Shivani takes a break by attending her college batchmates' reunion, where she reconnects with Parimal (Anupam Kher), her boyfriend in college. Parimal, who lives in Kolkata, is a widower who wants his daughter to rejoin her husband in London. Kajol’s youngster Thumri aka Chumki (Sara Ali Khan) works as an HR in a Delhi-based company and happens to travel to Bengaluru for work where she meets Parth (Aditya Roy Kapur) who is a travel blogger and has no plans for the future. Parth is friends with Shruti (Fatima Sana Shaikh) who wants to start a family but her husband, Akash (Ali Fazal) who works as a software developer, wants to quit and try his luck in movies as a playback singer. Thumri is going steady with her office colleague and boyfriend, but is not sure about him. One day, she calls it quits and goes to meet Parth, who is all set to get married. Akash shifts to Mumbai to begin his struggle as a singer. What do these couples do next forms the rest of the story.