Cathy began playing golf at age 7 while living in Kitty Hawk, NC. Her Junior golf accomplishments include the 1980 Orange Bowl International and 1981 PGA National Junior Championship. She represented USA on 2 PGA Junior Cup Teams and was a 2-time Golf Magazine All-American and 2-time AJGA All American.
Cathy played college golf for UNC-Chapel Hill before turning professional in 1985 where she won the Memphis State Intercollegiate.
She competed on the LPGA Tour from 1986 to 2006 and won 1990 DuMaurier Classic, an LPGA Major Championship. She also had 3 runner-up finishes while on tour.
Cathy now competes on The Legends Tour and is a member of the Legends Tour Board of Directors currently, serving as Co-Vice President. She is a dual member of the LPGA Tour and LPGA T&CP Division. where she won the 2017 LPGA T&CP National Senior Championship.
The biggest influence in golf was her father, Johnny, a former PGA Professional and former golf coach at Wake Forest. Brother Clyde is a golf course architect and past president of the ASGCA. For 12 years, Cathy hosted the Cathy Johnston-Forbes Easter Seals/UCP Golf Tournament near Wilmington, NC.