Danny Vieira da Costa (born 13 July 1993) is a German professional footballer who plays as a right back or right wing-back for Bundesliga club Mainz 05.

With his club having already advanced to the knockout stage of the Europa League, the 17-year-old da Costa made his Leverkusen debut as a second-half substitute against Atlético Madrid, coming on for Gonzalo Castro.

[5] da Costa made his club debut on 3 August 2012 against Energie Cottbus, and started the first two games of the season at right-back before being supplanted by Andreas Görlitz.

On 31 October 2014, in a match between the table leaders at the time, Ingolstadt and Fortuna Düsseldorf, da Costa suffered a leg injury in a collision with Lukas Schmitz, and had to be stretchered off.

[14] da Costa sustained an injury in training prior to the fourth match day, a partial tendon tear which caused him to miss around three months of the season.

[16][17] Initially behind Timothy Chandler on the depth chart at right back, da Costa played his way into manager Niko Kovač's plans as he started the final 13 games of the season.

[19] da Costa featured in Eintracht's team that won the 2017–18 DFB-Pokal against Bayern Munich, playing the forward ball that found Ante Rebić for the winner.

[27] After missing the 2015 UEFA European Under-21 Championship due to injury, da Costa was included in the provisional squad for the 2016 Summer Olympics in Rio de Janeiro.