The Dallas office of U.S. Immigration and Customs Enforcement announced the arrests Thursday.
ICE says it ran a five-day operation to arrest people who have convictions for sex crimes. About half of the 50 people arrested were from North Texas.
Eleven people had previously been deported and illegally re-entered the country. ICE says others arrested were sentenced and released without being identified immediately for a variety of reasons.
The people are being held at different jails throughout Texas.
Legal immigrants can be deported if they are found guilty of certain serious crimes.