The Tarkwa based side made the signings on transfer deadline day.
The players, left-back, Kingsford Baffoe and midfielders, Matthew Essiam and Frederick Kweigyah, joined the Yellow and Mauves on Monday at about 11:30 pm; 30 minutes to the closing of the transfer window.
Oil City FC announced the moves on Tuesday, May 29, 2018, through a press release.
Head coach of Medeama SC Samuel Boadu identified these players when his side beat the lower division side 2-1 in the Round of 64 in the MTN FA Cup.
The players despite being on the losing side impressed on the day and were targetted by Medeama.
The latest additions raise the number of incomings at Medeama to 14.
Before the start of this year's league, Medeama signed 11 new players which included former Kotoko midfielder, Kwame Boateng.
Medeama are currently topping the Ghana Premier League with 23 points from 12 games.