The 27-year-old Senegalese has been training with United over the last five weeks, having left Birmingham City in the summer. Jackie McNamara, the manager, was suitably impressed and the player needed little persuasion to sign a short-term contract
"The opportunity to get back playing at Dundee United makes me very happy," said Gomis. "I have great memories of Tannadice but I want to help create more good times for the club. After initially being offered the chance to keep my fitness level up, I have been impressed by the quality within the squad and have been welcomed by everyone."
McNamara said the decision to take on the midfielder again was easy but stressed it was not based on sentimentality: "I know United fans will have great affection for Morgaro for what he achieved here previously but I have decided to offer him a contract based on what he has shown me in training.
"His attitude, application and professionalism has been first class and added to the fact that he has excellent ability makes signing him an easy decision. Having him as part of the squad will allow me to select alternative tactics and formations at certain grounds and he brings great experience to the squad.
"This signing is very much about making the squad stronger and the length of deal will allow Morgaro and the club to see how the partnership can develop."
Gomis joined United from Cowdenbeath in 2007, playing 180 games and scoring seven goals in a four-year period. He joined Birmingham in May 2011 and made 44 appearances in his two years at St Andrew's.
United lie fifth in the league and Paul Paton, one of the many fresh recruits at Tannadice this season, says there is still plenty of work to be done. "You always hope you'll be up there. It's still early days and we're not taking anything for granted. It's a new team so we're gelling gradually with something like nine new faces, but the signs are positive."