Donald Trump celebrated the first anniversary of his presidential campaign at a Texas rally Thursday night by chiding Hillary Clinton, joking about his hair — and proposing an idea for a new cowboy hat.

“This is the one-year anniversary, and hopefully, we’re going to make it a worthwhile year,” he told the adoring crowd. “There are thousands of people outside who can’t get in. We’ll get a bigger venue next time.”

Trump hosted the rally at Gilley’s honky-tonk ballroom in Dallas, renowned as the location for the scene in the 1980 film “Urban Cowboy” in which John Travolta rides a mechanical bull.

“I read about this place,” Trump said. “Where’s that horse? I want to go on that horse!”

He also received what he called the “nicest” compliment from someone in the crowd who said she loved his hair.

“And it is my hair,” Trump said. “Did you get that on tape?”

He saw a protester being carried out while wearing a cowboy hat, and his business acumen kicked in.

“We’ll say ‘Make America Great Again’ on a cowboy hat,” Trump said.

He mocked Secretary of State John Kerry for falling off his bicycle last year amid Iran nuke-deal negotiations and breaking his leg.

“I promise I won’t be on a bicycle during a major negotiation,” Trump said. “I promise.”

He also took aim at President Obama for failing to defeat ISIS.

The rally offered supporters red meat in the deeply red state.

“We love Texas. We’re going to win Texas,” Trump said.

The speech was interrupted a several times by protesters, but they were mostly drowned out by enthusiastic supporters.

Trump said he expects that ­defeating Clinton in November will be more difficult than his primary victories because of the “dishonest” press.

He slammed her stance on gun control.

“I’m going to save your Second Amendment, folks,” Trump told the pro-gun crowd.

“Hillary will abolish the Second Amendment. Remember that.”

Outside, Trump supporters were legally carrying assault rifles as protesters jeered and mocked them with signs.

One protester, holding daisies, walked up to an armed man and placed a flower in the barrel of his rifle. The image was reminiscent of a photo taken during a Vietnam War protest in the 1960s.