López joined Serie A club Roma on 9 July 2019 on a five-year contract, for a reported fee of €23.5 million. He made his debut on 25 August in a 3–3 home draw with Genoa, making a further 31 appearances by the end of the campaign for the fifth-placed team. On 26 January 2020, he made a mistake in the Derby della Capitale to gift a goal to Lazio's Francesco Acerbi in a 1–1 draw.