 On 31 January 2018, Spanish club Real Sociedad announced the transfer of Moreno from Roma for €6 million, signing with the club until 2021.On 15 February, he made his competitive debut for "La Real" against Red Bull Salzburg in the Europa League, playing 76 minutes in the team's 2–2 draw.During midweek training, however, Moreno suffered a grade 1 injury to his internal obturator, meaning he would be ruled out for an undisclosed period of time.