2018 FINA World Swimming Championships (25 m) – Men's 4 × 50 metre medley relay

The Men's 4 × 50 metre medley relay at the 2018 FINA World Swimming Championships (25 m) was an event held as part of the short course world championships. This relay event consists of four swimmers, each swimming a 50-metre leg in a different stroke, in the following order: backstroke, breaststroke, butterfly, and freestyle.

The competition involved national teams, each selecting its four fastest swimmers proficient in the required strokes to represent their country. The swimmers' individual times are combined to determine the team's overall time, with the fastest overall time winning the gold medal. Silver and bronze medals are awarded to the teams finishing second and third, respectively. The event is governed by the rules and regulations set forth by FINA (Fédération Internationale de Natation), the international governing body for aquatic sports. The championships provided an opportunity for swimmers to showcase their talent in a short course (25-metre pool) setting and compete for world titles in the specified relay.

The final result determined the world champion for that specific year in the men's 4x50 metre medley relay in a short course pool. Results, including times and team compositions, are typically recorded and maintained by FINA as part of the official record for the event.