April O' Neil(Dimension Third Earth)

In the 2003 cartoon series, April, voiced by Veronica Taylor, got a costume change for the new incarnation of the animated series produced by 4Kids Entertainment. However, her role was similar to that of the Mirage Studios character: again, she served as an assistant to Baxter Stockman until his Mouser experiments got out of control, and after the Turtles saved her she became a faithful friend, ally, and "big sister" to them. April made much more use of her scientific expertise and she often used her computer skills to aid the Turtles. She developed a closer relationship to Donatello, who shared many of her interests. In Season 7 she sometimes helped Donatello to collect Splinter's data bits. April developed a modest knowledge of combat skills after training with Splinter. Her quick thinking was often instrumental to the Turtles' survival.

April is romantically attracted to Casey Jones, though their contrasting personalities often make them bicker. By the third season, the two seemed to have quite a serious romantic relationship. In the series finale's episode, "Wedding Bells and Bytes", she and Casey finally got married.