[7] On 11 July 2012, after failing to make a single appearance for Real's first team,[8] Carvajal signed a five-year contract with Germany's Bayer Leverkusen for a transfer fee of €5 million.

[9] Carvajal made his Bundesliga debut on 1 September 2012 in a 2–0 home win against SC Freiburg,[10] being subsequently named to the Team of the Week.

[13] On 3 June 2013, Real Madrid exercised their buy-back option on Carvajal, who became the team's first signing for 2013–14 for a fee believed to be in the region of €6.5 million.

This was confirmed by Bayer's director of football Rudi Völler, who stated: "Real Madrid noticed the outstanding performances by Dani this season, and it was only a matter of time before they exercised their buy-back option.

[16] One month later he played his first match in the UEFA Champions League, again featuring the full 90 minutes in a 6–1 away victory of Galatasaray in the group stage.

[21] In the first leg of the Champions League's semi-finals, on 5 May 2015, he conceded a penalty by fouling Carlos Tevez, with the Juventus forward converting the spot-kick to defeat the Spaniards 2–1.

[23] He contributed with eight appearances and one goal against Shakhtar Donetsk,[24] in the campaign's Champions League, as the tournament ended in win; in the final against Atlético Madrid, he was subbed off injured early into the second half of a 1–1 draw (penalty shootout triumph).

[25][26] On 9 August 2016, Carvajal started in the UEFA Super Cup clash against Sevilla in Trondheim, and scored the final 3–2 in the 119th minute after an individual effort.

[36] Early in the following month, he was sidelined with a heart condition;[37] he made eight appearances during that year's Champions League,[38] and Madrid won their third consecutive and 13th overall title in the competition.

In the decisive match against Liverpool he was forced to leave the pitch due to an injury, in an eventual 3–1 win at the Olympic Stadium in Kyiv.

[58] He retained his place in the starting line-up for the final Group B fixture against Morocco, assisting Iago Aspas' stoppage time equaliser in the 2–2 draw.

[60] He once again missed out on the European Championships three years later, with manager Luis Enrique leaving him out of the Spain's UEFA Euro 2020 squad due to injury.

[62] Carvajal was included in Spain's squad for the 2022 FIFA World Cup in Qatar,[63] playing the full match against Germany[64] and the second half against Japan[65] during the group stage, as the team was again knocked out at the round of 16 in a penalty shootout against Morocco.

[70] In the quarter-finals against hosts Germany, he was sent-off for a double booking late into extra-time for preventing a counter-attack, ruling him out of the next match; Spain won 2–1 to go through to the semi-finals.