After graduation, Tenney studied at Julliard, but took a break to join the national touring company of Tom Stoppard's The Real Thing, directed by Mike Nichols. While playing the title role in an off-Broadway production of Tartuffe, he was cast in Up in Saratoga, which subsequently led to his being cast as the lead in Romeo and Juliet at the Old Globe Theatre in San Diego. A newspaper review of the production came to the attention of the producers of the TV hit, Murphy Brown, who cast Tenney as Miles' older brother, a guest-starring appearance that launched his career on television. 

Jon appeared on many series throughout the first few years of his career including Crime & Punishment, Dirty Dozen: The TV Series and most notably ABCs Drama Equal Justice which ran in 1991 and co-starred Sarah Jessica Parker 

Jon has had numerous starring roles on and off-Broadway shows. His biggest to date being The Heiress where he preformed the starring role opposite Joan Allen. Many of the off-Broadway shows Jon starred in include, Brighton Beach Memoirs Biloxi Blues, The Substance of Fire, Sweet Sue, Beggars in The House Of Plenty and A Shayna Maidel.

In 1993 Jon was set up on a "blind date" with a young actress, who had herself vowed to never again date an actor. During the course of the evening, this young actress felt ignored and decided to finish her conversation with a ficus plant, it was at this moment that Jon fell in love with Teri Hatcher. They wed on May 27, 1994 in Jon's hometown and spent their honeymoon in New York city. Making spots in Greenwich Village and Fao Swartz where Teri bought Jon a model airplane and Jon purchased a teddy bear for his bride. 

Teri explained this in ecstatic detail when she appeared on the Regis & Kathie Lee show, where after sighs from the audience and Regis she added "and we had sex" where to Kathie Lee replied, "Not in FaoS wartz!" The woman does have her moments. 

Marriage can be hard when you are separated from your spouse. While Teri was in Los Angeles filming Lois & Clark, Jon was in New York appearing on stage in The Heiress. 

Love has no bounds, as Teri would get on a plane on Friday night, fly to New York to spend two days with her husband, then get back on a plane on Sunday to go back to her job. 

In 1996 Jon started work on a new show for CBS titled Good Company. It was an ensemble cast, but Jon was the star (his name was first), making it easier on the marriage because now both Jon and Teri were in LA and both were working. 

Good Company was canceled by May, after only six excellent episodes aired. After this, Jon went back to the stage, but this time it was in Los Angeles. 

Just as Jon's film career was taking off in movies such as Fools Rush In co-starring Matthew Perry and Selma Hayek and the Showtime channels Twilight Of The Golds, Teri's seemed to be crashing. Despite strong scripts and even stronger acting, Lois & Clark was falling in the ratings,  mainly due to ABC's lack of advertising,  and after numerous rumored reports, Lois & Clark was canceled May 21, 1997. 

The cancellation may have just been a blessing in disguise for Teri, just as her tv life was ending, her real life was growing. On May 2, 1997 the whole country, and even the world knew what Teri and Jon had known for weeks prior, that Teri was pregnant with their first child. 

In September of 1997, Jon's new Steven Bochco cop drama Brooklyn South premiered to rave reviews, and on November 10, 1997 Jon  and Teri welcomed their new daughter, Emerson Rose, into the world. 
Unfortunately someone has to lose in the ratings war, and Brooklyn South was falling far in that department; by the end of the season in April 1998, everyone knew the show would not be coming back for another year 

It's been over a year since Brooklyn South ended and in that time Jon has appeared on variety shows and an off Broadway play with Holly Hunter titled The Impossible Marriage which remained sold out throughout it's performances.
Jon's new show Get Real premiered on September 8th, 1999 on FOX to mixed reviews and only lasted one season before it was cancelled in May 2000.

Unfazed as always, Jon went on to star in Current Events, an off-Broadway play about a young boy confused about his sexuality. Jon portrayed the boys ever busy uncle and was of course, excellent. I was able to see the play from the first row and can attest to Jon's greatness on stage.

Jon also co-starred in the Sundance Film Festival Grand Prize Winner "You Can Count On Me" with Laura Linney and Matthew Broderick. This film is also a top contender for an Oscar Nomination.

In June 2001 Jon's  NBC sitcom "Kristin" co-starring Tony Winner Kristin Chenoweth premiered, unfortunately it only lasted six episodes. 

In April 2003 Jon and Teri's marriage ended and now they now share custody of Emerson Rose. You can now catch Jon in the TNT original series The Closer.