The news media have a strong influence on people’s perception of reality. But despite claims to objectivity, media organizations are, in general, politically biased (Patterson & Donsbach, 1996; Gaebler, 2017). The link between news media outlets and political organizations has been a critical question in political science and communication studies. To assess the closeness between the news media and particular political organizations, scholars have used different methods such as content analysis, undertaking surveys or adopting a political economy view. With the advent of social networks, new sources of data are now available to measure the relationship between media organizations and parties. Assuming that users coherently retweet political and news information (Wong, Tan, Sen & Chiang, 2016), and drawing on the retweet overlap network (RON) method (Guerrero-Solé, 2017), this research uses people’s perceived ideology of Spanish political parties (CIS, 2020) to propose a measure of the ideology of news media in Spain. Results show that scores align with the result of previous research on the ideology of the news media (Ceia, 2020). We also find that media outlets are, in general, politically polarized with two groups or clusters of news media being close to the left-wing parties UP and PSOE, and the other to the right-wing and far-right parties Cs, PP, and Vox. This research also underlines the media’s ideological stability over time.