The Clever Boys have snapped up Mncwango, Johannes and Denis Weidlich on pre-contracts, which will see the trio move to Milpark at the start of July.
The club also announced the signing of former Orlando Pirates midfielder Gyimah from Swedish club Helsingborg, while confirming the return of Sifiso Myeni from a loan spell with SuperSport United.
Bidvest Wits have confirmed the “precontract” signing of Thobani Mncwango, Robyn Johannes & Denis Weidlich with effect from 1 July 2018. Edwin Gyimah has also signed with our club with effect from 1 January 2018. Sifiso Myeni has been recalled from his loan with immediate effect.— Bidvest Wits (@BidvestWits) January 2, 2018
Mncwango's contract with Polokwane City is set to expire at the end of the season, after joining from Baroka at the start of the 2013/14 campaign.
The 30-year-old striker has made just two appearances for Rise and Shine this season, but managed his best figures of 13 goals in 29 league apperances back in 2015/16.
Johannes, who currently captains Cape Town City, had been offered a bumber new deal by the Citizens but has opted instead for a return to Gauteng.
The 31-year-old centre-back previously turned out for University of Pretoria, Mamelodi Sundowns and Pirates, and has been a key figure this season, having started 18 of their 20 games in all competitions thus far.
Weidlich is also a 31-year-old centre-back who joined Maritzburg United at the beginning of last season, and has managed 44 appearances in all competitions for the Team of Choice thus far.
Meanwhile, Gyimah started training with Wits in November last year after the Swedish league ended.
Despite leaving the Buccaneers and signing a two-year deal with Helsingborg in March, the 26-year-old has decided to return to South Africa to work with his former SuperSport mentor Gavin Hunt.