Given that serve velocity has been identified as one of the most important components influencing performance in tennis, identifying the factors associated with serve velocity is crucial for coaches and athletes. The aim of this study was to describe the relationship between physical performance, anthropometric characteristics and stroke velocity in youth tennis players. Twenty-seven youth players (male = 16, age = 15.69 ± 1.70 years; female = 11, age = 15.82 ± 1.40 years) underwent an anthropometric and physical performance assessment. On a tennis court, players were assessed for forehand, backhand and serve velocities. Pearson’s correlation coefficient revealed that forehand velocity was significantly correlated with height (r = 0.58) and handgrip strength (right hand: r = 0.68; left hand: r = 0.57), whereas backhand velocity was significantly correlated with running time (r = 0.52) and handgrip strength (right hand: r = 0.67; left hand: r = 0.55) in males. Similarly, in males, serve velocity was significantly correlated with height (r = 0.60), running time (r = 0.62) and handgrip strength (right: r = 0.77, left hand: r = 0.71). In females, a significant correlation was only demonstrated between serve velocity and body weight (r = 0.69). These findings highlight that handgrip strength, running time and body height variables are positively associated with stroke velocities in male youth tennis players.