Santiago Giraldo Salazar (Latin American Spanish: [sanˈtjaɣo xiˈɾaldo salaˈsaɾ], born 27 November 1987) is a Colombian former professional tennis player.

Throughout his career he has beaten several ex-number-one players such as Lleyton Hewitt, Juan Carlos Ferrero, and Andy Murray as well as some top-ten players such as Jo-Wilfried Tsonga, Kei Nishikori, Marin Čilić, Milos Raonic, Dominic Thiem, Gilles Simon, Jürgen Melzer, Rainer Schüttler, Tommy Robredo, Janko Tipsarević, and Nicolás Lapentti.

He has beaten golden-generation players from Argentinian tennis such as Gastón Gaudio, Guillermo Cañas, Mariano Puerta, Juan Martín del Potro, and David Nalbandian.

In October 2003, at age 15, Giraldo became the youngest player in his country to be ranked by the ATP, getting his first point with the ITF Futures tournament in Medellín.

Although he lost to the Spanish Fernando Vicente in the Challenger de San Luis Potosí, he was close to the Top-100, reaching position 115, and also entered the Roland Garros' main draw as a "lucky loser".

His only ATP triumph in 2007 was beating the Venezuelan Yohny Romero in the Davis Cup, helping Colombia win the series, 3–1, against Venezuela.

He made it to final draws five times, including the ATP World Tour Masters 1000 tournaments at Indian Wells and Miami.

Giraldo opened 2009 by winning the Challenger de Salinas title, defeating Michael Rusell in the final, and, in March, had his sole triumph at the ATP level in the Davis Cup match versus Uruguay.

One month later, Giraldo won the Challenger de San Luis Potosí's title against the Italian Paolo Lorenzi.

For the third consecutive year, Giraldo entered the Roland Garros' main draw, losing to Denis Istomin in five sets in the first round.

He beat Marcel Granollers and Guillermo García López at Viña del Mar to reach the semi-finals, where he was defeated by Leonardo Mayer.

Giraldo won the Advantage Cars Prague Open, which included an impressive win in the quarter-finals against world number-26 Martin Kližan.

Giraldo has a powerful forehand stroke—with a big backswing and a forward swing that contacts the ball with extreme speed, flattening it out—that he uses to move his opponents around and end points quickly.

Because of his shot-making and hyper-aggressive style of play, he is more than prone to making unforced errors on his groundstroke rallies, more often than on his returns of serve.

Giraldo occasionally exhibits clumsy footwork as well, and sometimes is simply not fast enough to retrieve directed or drop shots.