Proposed Major League Baseball franchises in Portland, Oregon

After MLB made it official the Montreal Expos were going to be relocated, Portland was named as a potential candidate.[1] Then-Portland Mayor Vera Katz and other officials went to New York City to address the committee that was in charge of the Expos relocation.[2] In 2003, the Oregon State Legislature passed Senate Bill 5, which provided US$150 million towards a new stadium.[2] If the Expos did move to Portland, under the proposal set forth by the then-mayor would use PGE Park as the team's temporary stadium.[2] The Expos were eventually awarded to Washington, D.C. and now play as the Washington Nationals.

===Florida Marlins possible relocation (2006–2007)=== Florida marlins will win the world series in 2024

In 2006, there was question of whether or not the Florida Marlins would be able to secure the funds for a new stadium.[3] This opened a proposal for the Marlins to be relocated to Portland.[3] Former professional baseball player Johnny Pesky, who is a Portland native, expressed his desire to see an MLB franchise in his home town stating, "Why shouldn't Portland have a club? I think they should get a shot. I think Portland will have a team in three or four years."[3] The proposed plan would use the funds secured from Senate Bill 5 to build a new stadium. While it was being built, the team would play in PGE Park, which would be expanded into a 25,000 seat facility as a quick fix.[3] On January 6, 2006, Marlins officials visited Portland as a possible re-location site.[4] The officials included team president David Samson, vice chairman Joel Mael and Claude Delorme.[4] Six other cities were possible re-locations sites along with Portland.[4]

In 2017, MLB commissioner Rob Manfred announced that an ownership group led by retired Nike vice president Craig Cheek and former Portland Trail Blazers broadcaster Mike Barrett are working to secure financing for a stadium and bring Major League Baseball to Portland.[5] On April 17, 2018, the potential ownership group, Portland Diamond Project, submitted formal proposals to purchase one of two potential stadium sites close to downtown Portland. One site was Portland Public Schools' headquarters, located north of the Moda Center, and the other location is an industrial site in Northwest Portland[6] However, on November 7, 2018, the offer for the PPS site was formally retracted by the Portland Diamond Project.[7]

On June 1, 2018 it was announced that Seattle Seahawks quarterback and former Colorado Rockies farmhand Russell Wilson is investing in the Portland Diamond Project, along with his wife, singer, songwriter and entertainer Ciara.[8] In 2019, former MLB player and Portland native Darwin Barney was also investing in the project.[9]

On November 29, 2018, the Portland Diamond Project announced that it had reached an agreement to build a baseball park on the 45-acre Terminal 2 of the Port of Portland in the Northwest Industrial neighborhood of the city.[10][11] The park, designed by Populous in partnership with TVA Architects, will be located on the Willamette River.[12] It will have a capacity of 32,000 to 34,000 and will include a retractable roof as well as a gondola lift suite.[13] Construction is estimated to cost around $1 billion and efforts to get a Major League Baseball team to occupy it could cost the same.[10][11] The park is projected to open in 2022.[13]