Rio rhymes with:
reo, castillo, castio, cleo, clio, deo, galileo, geo, keo, keogh, keough, leo, mckeough, meo, neo, reo, seo, seow, theo, tokio, toshio, trujillo, yeo, yoshio, yukio, zedillo
Rio sounds like:
r, r., ra, rae, rah, rahe, rahway, rai, raia, rao, rara, rare, rarer, rau, rauer, rauh, raw, rawe, ray, raya, raye, re, rea, rear, reay, ree, reeh, reh, reha, rehear, reher, rehire, rehor, reier, reiher, reo, rew, rewey, rewire, rey, reyer, rha, rhea, rhee, rhew, rho, rhorer, rhue, ria, riera, riha, ro, roa, roar, roe, roehi, roehr, roh, rohe, roher, rohr, rohrer, rohwer, roi, rorer, rorie, rorrer, rory, row, rowe, rower, roy, roye, royer, ru, rua, rue, ruh, ruhe, ruhr, ruwe, rye, ryer, ryohei, ryrie