One group of particularly enthusiastic fans named The Trump Tribe of Texas were pictured on the first day of the three day convention wearing coordinated shirts that spelled out the former presidents' first name.
In the photo, they can be seen participating in prayer in their matching yellow and red t-shirts and American flag hats. Launched in 1974, the annual conference is a key date for Republican leadership hopefuls and party figureheads.
Aside from Mr Trump, speakers at this year's event will include Fox News Host Sean Hannity, Texas senator Ted Cruz and Nigel Farage.
Mr Trump has continually teased that he is thinking of running again for president as the Republican candidate in in 2024, but has yet to formally announce his bid. However, he remains a significantly influential figure on the party and among its conservative supporters.