Ronan has played 13 times for Wolves after progressing through the club’s Academy.
Last season he spent time on loan at Portsmouth and now completes four-month move to Walsall in League One.
He’s joined by Johnson, who gained experience on loan at Telford last season and has agreed a season-long loan with the Saddlers.
Walsall have enjoyed a strong start to the League One campaign, sitting in a Play-Off positions going into tomorrow’s game at home to Blackpool.
Meanwhile, McKenna has made a loan move to Telford in National League North.
The Irishman has previously spent time on loan at Belvedere and Bray Wanderers, and will now remain with Telford until January.