The MTV reality show, which made the 23-year-old star famous and brought her together with husband Spencer Pratt, is being axed after six seasons.
But Heidi told People: "I'm so excited The Hills is finally over and I can now become a full time motion picture actress - there is no better training [for an actor] than being in front of the cameras 24-7 - I'm now finally free to start my career and my new life as a female mogul in Hollywood!"
Heidi added: "After working with Oscar-winner Ron Howard on a short film project [for FunnyorDie.com] and then working for days with the comedic genius director Dennis Dugan and his team of brilliant comedy visionaries at Happy Madison on Just Go With It starring Adam Sandler and Jennifer Aniston, I have been able to truly find what makes me the happiest in life."
The reality TV star revealed what makes her happy, saying: "Getting to truly show the world my creative ability while playing... different characters."
She also revealed she wants to star as "a lifeguard named Summer" in a script she wrote herself.
Heidi said: "I am making the first 3-D beach comedy about a shark that attacks a small beach town and I save the day with my 3-D boobs. I've even written a role for Dolly Parton to play the town mayor!"