Romaine Vincelot and Adam Armstrong scored the goals to win the game for the Sky Blues.
The game took a while to get going but it would be Latics who had the first opportunity of the game on eight minutes.
Curtis Main was fouled 30 yards from goal but Brian Wilson’s free kick hit the wall.
Coventry City had the best chance of the half on 10 minutes as Jack Stephans had space at the back post from a corner but volleyed wide of the post.
That was a let off for Latics and they had to do some defending soon after.
Adam Armstrong, who was a threat throughout the first half, hit a free kick over the crossbar, whilst at the other end, Liam Kelly struck over the crossbar from 25 yards.
Athletic’s best chance of the half came midway through the half as Dominic Poleon crossed into the centre for Main and he forced a smart save from Reice Charles-Cook at the back post.
Two minutes later, Main again forced a good save from the goalkeeper as he denied him from the edge of the penalty area.
Brian Wilson almost scored his first league goal of the season as he cut inside from the left and unleashed a fierce strike but it went inches wide of the goal.
Coventry had two chances to take the lead before half time as Armstrong knocked the ball past Joel Coleman but B.Wilson was there to clear the danger.
On the stroke of half time, Armstrong again got beyond Coleman but was forced wide. He did eventually cross into the box but George Thomas fired over the crossbar.
It was a quiet opening to the second half as the game did start to have an end of season feel to it.
Forte and Poleon were causing a threat in attack but the ball just was not sitting for Latics.
A flurry of changes really affected the flow of the second half with neither side really forcing chances.
With 15 minutes of the game remaining, Coleman pulled off a superb save to deny Armstrong from five yards out.
However, from the resulting corner came the opening goal of the game as Vincelot headed home at the front post to nod the Sky Blues into the lead.
Five minutes later, Coventry City extended their lead as Armstrong scored his 20th of the season, firing low past Coleman to seal the game.
Main had a chance before the full time whistle as he shot wide with the outside of his boot from inside the penalty area.
However, that was the best chance Latics could muster as they fell to defeat in the final game of the season.
Oldham Athletic: Coleman, Dummigan, J.Wilson, Gerrard, B.Wilson, Dieng (Croft 72’), Kelly, Winchester (Jones 60’), Forte, Poleon (Cassidy 68’), Main.
Subs not used: Cornell, Brown, Mills, Edmundson.
Coventry City: Charles-Cook, Vincelot, Fleck, Armstrong, Stephans, Rose (Kelly-Evans 46’), Harries, Thomas, Hunt (Murphy 66’), Lameiras (Gadzhev 59’), Bigirimana.
Subs not used: Tudgay, Stevenson, Addai, Jones, Kelly-Evans.
Goals: Oldham Athletic 0-2 Coventry City (Vincelot 74’, Armstrong 80’)
Attendance: 4,928 (782 visiting supporters)