Danielle Denise O'Toole-Trejo (born July 7, 1994) is a former professional softball pitcher and current assistant coach for Stanford.

[4] She also began a career best shutout streak in that game that went on for 22 innings, during which the Aztec struck out 18, allowed 21 hits and two walks for a 1.04 WHIP.

[7] O'Toole redshirted in 2015 after transferring to play for the Arizona Wildcats and as a junior in 2016 was named All-Pac-12 and posted her best shutouts total.

In the only non-decision of the streak vs. the Oregon State Beavers, O'Toole set a career best with 10 strikeouts in just four innings of work on March 19.

[14] On May 20 in the Regionals of the NCAA Tournament, she threw a 7 strikeout, 1-hit shutout to tally her 100th career victory over the South Carolina Gamecocks.

At the 2020 Summer Olympics, O'Toole threw 17.0 innings for Team Mexico, allowing three earned runs, 13 hits and two walks for a 1.23 ERA and 0.88 WHIP, with seven strikeouts and no errors on the mound.