Johnson is one of the better prospects making his way through the ranks at Old Trafford and has been allowed to move to Highfield Road to accrue experience.
The teenage striker spent the second half of last term on loan at United's feeder club Antwerp and will now enjoy a full campaign in The Championship.
He links up with former Red Devils trainee Neil Wood at Coventry and Sky Blues boss Peter Reid is happy to have Johnson at his disposal.
"Eddie is a big, strong lad and I think he will do a good job for us," said Reid.
"He is an England Under-19 player and has a good pedigree so he will have a great attitude as well as ability."
Reid is also seeking to strengthen his defence with the capture of Camille Borios, who has impressed on trial.
The Sky Blues are keen to discuss a deal with his club Marseille, although Reid has ditched his interest in another trialist - Israel international Ilan Bachar.
"We have let Ilan go but we'll hopefully be having a chat with Marseille in the very near future about Camille and we'll go from there."
Meanwhile, Coventry have taken goalkeeper Gavin Ward back - just a month after leaving.
The 34-year-old is on a month-to-month contract.
