Katherine Hillard (played by Catherine Sutherland) is the Pink Power Ranger of the third generation, in the series Mighty Morphin' Power Rangers.

Kat came to Angel Grove from Australia as a junior in high school. Rita Repulsa had made her her evil spy and gave her dark powers as well as the ability to turn into a cat. She had to be found by Kimberly Hart and Aisha Campell, the Pink and Yellow Rangers, as a cat and was adopted by them. She spies on the Rangers to gain information on their lives.

Kat stole Kim's power coin which made Kim weakened. Using the coin, she was able to break into the Falconzord and capture it, rendering the other Ninja Zords useless.

When Kimberly fell at the Youth Center due to her weakened state, Kat felt responsible, as she felt guilty, which made broke the spell that Rita had over her.

Kat had returned Kim's Power Coin and became her replacement as Kim left for the Pan Global Game. She controls the Crane Ninjazord and became the Pink Ninja. She copilots with Thomas Oliver, the White Ranger, in the White Shogunzord. There was a point where she wanted to date Tommy, but it never got to that until they were no longer Power Rangers. The bond that did develop was first shown when she was able to break the control Prince Gasket had over Tommy after a long brainwashing.

After the Ninja powers were destroyed, Kat had to travel to Australia to find the pink Zeo Subcrystal.

Kat became the Pink Zeo Ranger (Zeo Ranger I Pink), piloting the Zeo Zord I and Super Zeo Zord I.

Kat later became the Pink Turbo Ranger and controls the Wind Chaser Turbozord.

Kat recently graduated Angel Grove High and helping out freshmen. She gave her powers up to Cassie Chan to pursue other things in life. She is currently attending the Royal Dance Academy in London.

At some point in an alternate timeline, she weds Thomas Oliver and they have a child together.