She was 17 when her older brother, comedian Andy Jones, put in a good word for her with the Newfoundland Traveling Theatre Company.

After a summer touring with this company Cathy joined Tommy Sexton, Greg Malone, Mary Walsh, and Dyan Olsen in Toronto to look for more work in theatre and there in the fall of 1973, they formed the comedy troupe CODCO.

In 1992, Jones, comic Rick Mercer and former CODCO co-stars Mary Walsh and Greg Thomey created a new television series, This Hour Has 22 Minutes.

In 2020, Jones reprised her longtime 22 Minutes character of Miss Enid in the CBC Gem web series Broad Appeal: Living with E's.

A CBC Life and Times biopic titled Keeping up with Cathy Jones was produced in 2006 by Lynne Wilson, directed by Barbara Doran, and featured several of her co-stars from both CODCO and This Hour Has 22 Minutes including Greg Thomey, Rick Mercer, Greg Malone, and Andy Jones.