While at  UCLA, she took part in several photo-shoots for some magazines, and slowly and decided she wanted to become a model actress. She quit her studies and began to take private classes in dance and acting.

Her first television acting role was one line on the sitcom Sugar and Spice (1990).  This was followed by her role  as Marine Lieutenant Colonel, Sarah MacKenzie, in the series JAG She played this role from 1995 until 2005, and it became the role for which she is most well-known.

Since 2007 Bell has starred in Lifetime's  drama series Army Wives as Denise Sherwood, the wife of a U.S. Army lieutenant colonel. Bell also has  acted in the main role of Hallmark's The Good Witch , and its sequels The Good Witch's Garden , The Good Witch's Gift , and The Good Witch's Family . In addition to acting in all the movies she was also the co-executive-producer.

She met Adam Beason in 1992 on the sets of the film, ‘Death becomes her’. They fell in love and she married him in 1994. She has a son and a daughter through this marriage. She got separated from her husband, in 2011. She was also rumored to have dated Terry Serpico.

She talked a lot about her life with Adam, how she got ready to become a mother. However, she never stated the reason for the divorce. She said that Adam and she mutually agreed to end the relationship. She also said that she would remain in good relationship with him, for the sake of the children. It was said that Catherine initiated the process of separation and Adam agreed to the decision of his wife. The reason for the separation was rumored to be her affair with David Elliott.

She talked a lot about her life with Adam, how she got ready to become a mother. However, she never stated the reason for the divorce. She said that Adam and she mutually agreed to end the relationship. She also said that she would remain in good relationship with him, for the sake of the children. It was said that Catherine initiated the process of separation and Adam agreed to the decision of his wife. The reason for the separation was rumor

There are no evidences to prove this point, but, many people believed that there was a spark between David and Bell, when her marital relationship was failing. She did not mention him as her boyfriend, before and after the separation. As she never dated him after the separation, the rumor was a false alarm. Adam never talked about her, his relationship with her and other details about his marital life to the media. He always wants to keep a low profile. He is not known to have any girlfriend, when he got separated. Even after the separation, both of them managed their production company together, without much of a drama.

The separation settlement details are not known to the public. It was said that there was no alimony or spousal support. The child custody and child care support details are not known. After her separation from Adam, it was rumored that she has a few romantic relationships, but, none of them were serious. It is almost three years and both of them have not started their dating phase, yet. There were no concrete evidences for infidelity, physical violence or long term argument to be the reason for the separation. The sources near to them said that it was a surprise for them too.

They never talked about their personal issues to the media or used the social networking sites to quest their anger and thus, whatever happened to them, was kept private. Their separation was not an ugly one. There were no social media fights, trials and swearing in the public. The separation did not have any speculations which would have attracted a few journalist's attention. It was assumed that they had a pre-nup, but the evidences to point this are missing. There are a lot of rumors about her current dating life and the reason for the separation. She never commented on any of the rumors. The same goes with Adam too.

By grouping the collected information, it can be said that they were together for 17 years and then, they planned to get separated and had a smooth separation. Neither of them are in a serious relationship with anyone.

Though Bell was raised Roman Catholic she is now a practicing member of the Church of Scientology. As a Scientologist Bell has publicly supported many of their events and groups including Scientology's Hollywood Education and Literacy Project.