Rock Island is an unincorporated community and census designated place (CDP) in Colorado County, Texas, United States.

[18][16][17] The area was settled in 1896 as part of a land promotion scheme on the Texas and New Orleans Railroad.

The petition was granted and Charles Petersen was appointed the first postmaster of Rock Island on August 9, 1897.

[19] Dueling realtors' intent on outselling each other recruited land-buyers from Illinois, Iowa, and Missouri, promising a "tropical paradise" near the Gulf of Mexico.

[21] Public education in the community of Rock Island is provided by the Columbus Independent School District.