Language knowledge is not limited to linguistic competence; cultural norms of a society affect the way people communicate. In fact, culture, tradition, and values are realized and manifested through language and the use of units known as speech acts. The current study sought to explore the strategies used by 200 native Iranian speakers of Persian, 50 American native speakers of English, and 48 Iranian English as a Foreign Language (EFL) learners in producing the speech act of congratulations through the social network of Instagram. Participants were asked to comment in response to the post and congratulate the celebrity for their birthday. The content analysis of the congratulations corpus led to the emergence of eight categories of congratulation strategies for Iranian native speakers of Persian (the most frequent one: "statement of congratulations," n = 80, 58.39%), nine categories for the American native speakers of English (the most frequent one: "use of address terms," n = 44, 30.34%), and seven categories for the Iranian EFL learners (the most frequent one: "statement of congratulations," n = 28, 47.45%). Moreover, the results of Chi-square indicated that the three groups were different with regard to certain categories of congratulation strategies. The results can have important implications for EFL teachers and learners as well as textbook developers.