Danny Philliskirk had given Latics the lead early on and Forte extended that advantage on the half hour mark.
James Maddison pulled a goal back for the Sky Blues but Forte scored to regain the two-goal advantage just before the half time interval.
The home side put in a dominant second half display and made it four ten minutes from time as Jabo Ibehre notched his first goal of the season to put Latics a point outside the play off positions.
Latics started the game positively, retraining possession comfortably.
Their pressure paid off on nine minutes as they took the lead. Forte headed into the path of Philliskirk who jinked inside his defender and shot from the edge of the box to put Latics one to the good.
The home side were dictating the play and were in control of proceedings.
After enjoying large spells of possession, Latics doubled their lead just before half hour mark. Forte dispossessed Jordan Willis in defence before racing through and finishing confidently past Ryan Allsop for his ninth goal of this prolific campaign.
Athletic went in search of a third but Forte's deft flick though to Jabo Ibehre was just cut out by Andrew Webster.
Coventry, who were yet to test goalkeeper Paul Rachubka, managed to claw a way back into the game on 35 minutes.
Liam Kelly brought down Maddison on the edge of the area and the forward picked himself up to score the free kick via a deflection from the wall which wrong-footed the goalkeeper.
The goal did not affect Latics and Mike Jones almost sensationally scored from 40-yards when he spotted Allsop off his line but the goalkeeper appeared to palm the ball over the bar but the referee awarded a goal kick.
This riled the fans but they were soon cheering two minutes later as Forte extended Athletic's lead.
Ibehre's world-class ball over the top was matched with an immaculate touch from the forward and he confidently dispatched the gal past the goalkeeper to send Latics into the break with a comfortable lead.
Coventry were handed a golden chance to pull a goal back in the game two minutes into the second half. Jones' backwards header was capitalised on by Shaun Miller but the striker smashed the post from ten yards out.
Latics almost made their visitors rue that opportunity on 55 minutes as Forte almost notched his hat-trick. James Dayton's cross found the out-stretched leg of Forte but the forward guided his effort just wide of the post.
Coventry were just starting to impose themselves on the game but were finding clear-cup opportunities hard to come by with Timothee Dieng and James Wilson standing firm.
With 70 minutes on the clock, Ibehre tried his luck from 20 yards with a volley but Allsop managed to save comfortably.
Forte was soon substituted to the rapturous applause from the Latics supporters and Dominic Poleon took his place.
Latics started to regain control of the game and with only 15 minutes remaining Jones curled a free kick which was destined for the top corner but the goalkeeper clawed the ball away.
The momentum was with the home side and they made it four on 78 minutes. Genserix Kusunga played a inch-perfect ball into the box onto the head Ibehre and he guided the ball past the goalkeeper to put the game beyond doubt.
With Athletic in the ascendancy, they went in search of a fifth to boost the goal difference but Dieng, who had been assured all night, had his shot tipped behind on 88 minutes.
The home side saw out the game in a professional manner and extended their unbeaten run to 12 league games.
Oldham Athletic: Rachubka, Kusunga, J.Wilson, Dieng, Mills, Dayton (Tidser 79'), Jones (Winchester 82'), Kelly, Forte (Poleon 71'), Philliskirk, Ibehre.
Subs not used: Brown, Bove, Turner, Tyson.
Coventry City: Allsop, Willis, Webster (Tudgay 64'), Fleck, O'Brien (Thomas 74'), Miller (Jackson 64'), Barton, Phillips, Hines, Haynes, Maddison.
Subs not used: Burge, McQuiod, Coulibaly, Finch.
Goals: Oldham Athletic (Philliskirk 7', Forte 29', 41', Ibehre 78') 4-1 Coventry City (Maddison 35')
Attendance: 3,224 (223 visiting supporters)