Ohai, who is also engaged to Houston Texans star J.J. Watt, was drafted to Houston in the 2014 draft as the No. 2 pick.
SEE ALSO: Houston Dash star Kealia Ohai named RodeoHouston parade grand marshal
During her six seasons with the team, Ohai made 114 appearances and started 108 times. She owns the club record for goals scored, with 28, and has recorded 16 career assists.
"Any team in the league would jump at the opportunity to add Kealia to their roster," Red Stars Head Coach Rory Dames said. "She has proven her ability to score at this level and we are excited to get her integrated into our group. We look forward to having her here in Chicago."
Ohai was the second overall pick in the 2014 NWSL Draft and served as the team's captain for the past three seasons.
"I want to thank the entire Houston organization and the wonderful fans for my last 6 years as a Dash player," Ohai said. "I have created lasting friendships and Houston will always be my home. I'm excited for a new opportunity with Chicago and to become the best player I can be."
Ohai posted a heartfelt video on Twitter saying, "Houston will always feel like home."
Very proud of you and excited for you!!— JJ Watt (@JJWatt) January 6, 2020
I’ll hold it down here, you dominate in Chicago!
In order to acquire Ohai, the Red Stars traded defender Katie Naughton to Houston and the 18th overall selection in the 2020 NWSL College Draft.