The goal of the new legislation is to ensure that Catalan graduates "have no problems with English" when they leave university, something which is not the case at present.
A study by the OCU (Spain's Consumers and End-Users Organization) revealed that only one in ten graduates currently claims to have an advanced level of English, while a report published by the Cambridge University Press showed that only 13 per cent say they have a "high" or "very high" level.
University students graduating from 2018-2019 onwards will have to pass a test in English – or another third language – equivalent to level B2 (upper intermediate) in the Common European Framework of Reference (CEFR) for Languages.
The new law will apply to students at all of Catalonia's 12 public and private universities, according to newspaper The Huffington Post.
Similar measures have been implemented in other universities across Spain but most of them have set the bar lower, at lower intermediate (B1) level.
Union leaders reacted to the news by slamming the increased demands it would place on less wealthy students.
Juanjo López, of Barcelona's Student Union, claimed that, "Ultimately, what it is going to achieve is that only those with resources will get degrees while those who now have to work to pay tuition and have no time to study English outside the classroom will be hurt."
That argument was rejected by Pilar Garcés, coordinator of the English module in the Master of Teaching in Secondary Education at the University of Valladolid.
"You can work part-time in English-speaking countries and there are many free courses with which you can learn English without problems . English will exclude people from working in an international context if it's not learned," she said.
Others, such as Julio Redondas, Communications Director of Cambridge University Press, saw both sides of the controversy.
He claimed that it would create "difficult situations" because the current level of English teaching in Elementary and Secondary schools left many students entering university "far from B2 level".
These students would be "forced to make an extra effort to catch-up" which could affect their performance in the other academic subjects of their chosen career.
However, he added: "It's not the end of the world. I think you can get to B2 in four years... but I understand the students' arguments."
Compulsory English hit the headlines last week when it was revealed that basic knowledge of the language would soon be mandatory for taxi drivers in Seville, in the south of Spain, in order for them to receive their taxi licences.