WASHINGTON—Republican lawmakers on the House Intelligence Committee have drafted a report saying the panel’s yearlong probe into Russian election interference found no evidence that Moscow colluded with Donald Trump’s campaign or that the Kremlin favored Mr. Trump in the 2016 race.

The panel found “bad judgment” and some “inappropriate meetings” between members of the Trump campaign and Russians, but no sign that those amounted to collusion, said Rep. Mike Conaway (R., Texas), who has been heading the probe since last spring.

Mr. Conaway cited a much-scrutinized June 2016 meeting at Trump Tower in New York between a Russian lawyer linked to the Kremlin and top Trump campaign aides, including one of Mr. Trump’s sons and his son-in-law. “That meeting should never have taken place,” Mr. Conaway said. “But we can’t find anything that leads us to a collusion string.”

In the 150-page draft report, which committee Democrats haven’t seen yet, Republicans wrote that Russia carried out an “active measures” campaign in the 2016 election and was likely to do so again in future elections, but said they saw no sign that Moscow was seeking to help Mr. Trump, Mr. Conaway said.

The panel’s top Democrat, California Rep. Adam Schiff, in a statement Monday evening, called Republicans’ announcement a “tragic milestone for this Congress” and “yet another capitulation to the executive branch.”