The colonization of Mars proposes establishing permanent human settlements on the planet, a concept distinct from the exploration missions currently pursued by public space agencies, which primarily focus on robotic probes and potential crewed landings. While organizations like SpaceX, advocacy groups such as the Mars Society, and figures like Robert Zubrin actively promote colonization, public agencies often prefer the term "settlement" to avoid the sociopolitical connotations of "colonization."

Significant challenges to Martian settlement include intense ionizing radiation, pervasive toxic dust, a thin and unbreathable atmosphere, and extreme temperature fluctuations ranging from −70 to 0 °C. Although successful robotic missions, like the 1976 Viking 1 lander, have explored the planet, no crewed missions to Mars have yet occurred. Motivations for colonization span scientific curiosity, the opportunity to mitigate the risk of human extinction, the desire for an independent off-world colony, and the potential for economic exploitation of the planet's resources.