The deal was announced while the Rockies were playing the second game of a day-night doubleheader against Washington. Colorado had a solid lead for an NL wild-card spot.
Monday is the deadline for teams to make trades without waivers.
Lucroy hit .242 with four home runs and 27 RBIs in 77 games with Texas this year. While he made 65 starts at catcher, the Rangers also have Robinson Chirinos and Brett Nicholas on their big league roster.
"Getting Jonathan gives us a guy with some veteran presence behind the plate just like Ryan Hanigan as our young starters go into uncharted territory in the next two months,'' Rockies manager Bud Black said. "His track record is pretty good. The guy's an All-Star. He's had success in the major leagues both offensively and defensively, so we should feel good about this one. To get this type of player, it's going to pick everybody up.''
Rangers general manager Jon Daniels said the move gives his team an opportunity for Chirinos and Nicholas "to play more, and for us to add young talent to the organization.''
Lucroy had been with the Rangers for almost a full year, since they acquired him from Milwaukee last Aug. 1 -- the trade deadline day last season.
The 31-year-old Lucroy, a two-time All-Star with the Brewers, hit .276 with 11 homers and 31 RBIs in his 47 games at the end of last season with the Rangers, who won the AL West title.
Lucroy has thrown out 13 of 44 would-be base stealers this year. He has caught a major league-most 159 runners trying to steal since 2011.
Chirinos was the Rangers' opening day catcher in 2015 and 2016. The 32-year-old from Venezuela is hitting .216 in 46 games this year, with 12 homers that are only one shy of his career high.
Nicholas made his big-league debut with 15 games last season, and was recalled from Triple-A Round Rock last Monday after Chirinos hurt his ankle in a home-plate collision. Nicholas pitched the ninth inning in a 22-10 loss to the Miami Marlins on Wednesday night, and made his first appearance at catcher Sunday.