Peter Thiel, PayPal co-founder and one of Silicon Valley's elite entrepreneurs, will be the first openly gay speaker featured at a national Republican convention in 16 years. His appearance comes as party leaders refuse to soften the GOP's formal opposition to gay marriage.

Thiel, who has been a staunch supporter of Donald Trump's run for the oval office, previously supported Ron Paul for president and has identified himself as a convervative libertarian in the past.

He has been a hearty donor for Republican candidates, including Ted Cruz during his run for attorney general and fellow techie Carly Fiorina in her failed bid for the Republican nomination. Thiel also founded a student publication while at Stanford University that focused on politics that stray from the conventional two-party system.

There have been few openly gay speakers at the convention, the last being in 2000 when Rep. Jim Kolbe from Arizona nabbed a speaking spot when George W. Bush became the Republican nominee. Steve Fong, an adovcate for a gay rights group, also gave a short speech in 1996.

It's still unclear whether Thiel will be speaking about gay rights, although he has said in the past that he supports gay marriage and confirmed that he is a member of the LGBT community. The tech tycoon was outed against his will by Gawker Media, and secretely funded a lawsuit against the company earlier this year that saw it go bankrupt.

Other speakers will include four of Trump's children, Las Vegas casino owner Phil Ruffin, and actor and former underwear model Antonio Sabàto Jr. College football star Tim Tebow will appear on stage, the campaign confirmed.

Mark Geist and John Tiegen, survivors of the deadly 2012 attack on the American diplomatic consulate in Benghazi, Libya, will speak.

Some of the GOP's biggest names are declining to participate in four-day convention, which begins on Monday.

Presidents George H.W. Bush and George W. Bush, and the party's two most recent presidential nominees, John McCain and Mitt Romney, plan to skip the event, as does Ohio Gov. John Kasich, another Trump primary challenger.

Many have taken the Bush family absence to indicate strong disapproval for Trump, whose brash and often times politically incorrect campaign style clashes with the so-called "compassionate conservatism" favored by the former presidents.

Shrugging off such absences, Trump's team suggested the convention lineup would help highlight Trump's outsider appeal.

"We are totally over-booked. We have great speakers, we have winners, we have people that aren't only political people,'' Trump told Fox News Channel on Tuesday. We have a lot of people that are just champions and winners.''

He acknowledged in recent days that he'd stick a little closer to tradition.

"Look, I have great respect for the institution of the conventions. I mean to me, it's very important. So we're not going to change the wheel,'' he said on Fox.

The program will feature people such pro golfer Natalie Gulbis, retired astronaut Eileen Collins, and Ultimate Fighting Championship president Dana White. Former Navy SEAL Marcus Luttrell, author of the book, ``Lone Survivor,'' about a 2005 firefight in Afghanistan, will make an appearance, along with a Wisconsin sheriff, David Clarke, who is a vocal critic of the Black Lives Matter movement.

The convention will highlight religious leaders such as Jerry Falwell Jr. and Haskel Lookstein, the New York rabbi who converted Trump's daughter Ivanka to Judaism.

Trump does not forget his business relationships, giving speaking slots to real estate investor Tom Barrack and even the general manager for Virginia's Trump Winery, Kerry Woolard.

In a nod toward party unity, Trump will feature several former presidential competitors, including Cruz, Wisconsin Gov. Scott Walker, Ben Carson and Arkansas Gov. Mike Huckabee.

The real estate mogul announced Friday that he had selected Indiana Gov. Mike Pence as his running mate.