Born in Madrid to a Dominican mother, De Tomás joined Real Madrid's youth academy in 2004 after starting out at CD San Roque EFF. He played his first senior match on 8 April 2012, featuring the last 21 minutes for the C-team in a 2–0 home win against CF Pozuelo de Alarcón for the Tercera División championship. De Tomás was promoted to the third team in the middle of 2012, with the side now in Segunda División B. On 17 August 2012 he appeared in his first game for the reserves, coming on as a late substitute for Juanfran in a 1–2 away loss to Villarreal CF for the Segunda División. On 16 December, back with the C-side, De Tomás scored a hat-trick in a 5–2 home rout of CD Marino. He continued to represent both affiliates during the season, and was definitely promoted to Castilla in September 2013. De Tomás scored his first professional goal on 4 December 2013, netting the first in a 3–2 home victory over Girona FC. He contributed with a further six in 27 appearances over the campaign, as the B-team suffered relegation. In July 2014, De Tomás was included in the main squad for its pre-season trip to the United States. He made his competitive debut for them on 29 October of the same year, replacing Karim Benzema in a 4–1 away defeat of UE Cornellà in the Copa del Rey.
Loans
On 31 August 2015, De Tomás was loaned to Córdoba CF in a season-long move. Roughly one year later, he signed with Real Valladolid also in the second level and in a temporary deal. De Tomás was loaned to Rayo Vallecano on 1 September 2017. He was the second-highest scorer of the season with 24 goals, including hat-tricks in victories over Lorca FC, Cultural y Deportiva Leonesa and CF Reus Deportiu, as the club from Vallecas won the league and were promoted back to the top flight; this haul was a season record for any player in its history, and he was also named Segunda División Player of the Month in February and April 2018. On 17 June 2018, De Tomás signed a new contract with Real Madrid until 2023. Two months later, he was loaned to Rayo Vallecano for another campaign. He scored his first goal in the Spanish top tier on 22 September, but in a 1–5 home defeat against Deportivo Alavés. The following 11 January, also at the Campo de Fútbol de Vallecas, his hat-trick helped the hosts down RC Celta de Vigo 4–2.
On 9 January 2020, De Tomás returned to his country's top flight, signing for RCD Espanyol on a contract lasting until 2026. The transfer fee of €20 million was a new record for the club from Barcelona, nearly doubling the €10.5 million they paid for Matías Vargas; Benfica retained 20% of his future transfer fee. Three days after joining, he made his debut away to UD San Sebastián de los Reyes in the third round of the national cup, coming on in the 61st minute for Jonathan Calleri and wrapping up a 2–0 win. On 19 January, he started in his first league game and scored the decisive goal of a 2–1 victory at Villarreal CF; he scored in each of his first five games, triggering a clause that obliged Espanyol to pay Benfica a further €500,000.
Personal life
De Tomás' father, also named Raúl, was also a footballer and a forward. He spent most of his career in the Spanish third division. His younger brother, Rubén, came through the youth ranks of Rayo Vallecano.
