They will participate in an hour long 7 p.m. debate at the WFAA/Channel 8 Victory Park studio in Dallas.
The race remains more low-key than the brutal multi-million dollar GOP primary battle earlier this year that pitted Cruz against Lt. Gov. David Dewhurst.
At stake is who will replace Kay Bailey Hutchison in the U.S. Senate next year. Two third-party candidates were not included in the Belo-sponsored debate: Libertarian John Jay Myers of Dallas and Green Party candidate David Collins of Houston.
This is the first U.S. Senate seat in Texas since 2002. Political observers have long given the edge to the Republican in the race, since Democrats haven't won a statewide office in Texas in nearly 20 years.
Cruz and Sadler will also face off Oct. 19, in an hour long debate at PBS affiliate KERA-TV, Chanel 13.
-- Anna M. Tinsley