Among the inivestors in the for-profit marijuana-legalization plan are legendary basketball player Oscar Robertson, left; entertainer Nick Lachey, center; and two great-great-grandnephews of President William Howard Taft.

There is a doctor, a developer, an NBA legend, a fashion designer, a knight, an ex-boy-band member, a professional football player and two relatives of a U.S. president.

Despite their widely varied backgrounds, investors in the for-profit ResponsibleOhio marijuana-legalization plan have something in common: They all want to make money, and lots of it.

The 24 known investors bought into a plan establishing 10 exclusive commercial marijuana-growing sites across the state. The list of investors does not include those who bought shares from the original investors but whose names are not disclosed on U.S. Securities Exchange Commission forms.

If marijuana legalization is approved by voters in the Nov. 3 election, investors will spend hundreds of millions to build enclosed structures to grow pot...