Brennan began his dance training at a small ballet studio in South Dakota at age ten. He has attended summer training intensives with Los Angeles Ballet, Ballet West, Cecchetti Council of America International Summer School, Brigham Young University, and Central Pennsylvania Youth Ballet. He was a featured dancer on PBS’s South Dakota Symphony Young People’s Concert. He represented the United States at the Cecchetti International Classical Ballet competition in 2014. At age 16, Brennan was awarded a full scholarship and spent two years training full-time at CPYB, studying under Marcia Dale Weary, Alan Hineline, and Simon Ball. He was selected to work with guest choreographers Price Suddarth, Shayla Bott, Matthew Powell, and Simon Hoke. Brennan also worked as a guest artist for the Virginia Youth Ballet. Some of Brennan’s favorite roles have been Prince Desire in Sleeping Beauty, Franz in Coppélia, and Sugar Plum Cavalier in The Nutcracker. In his two seasons with the Saint Paul Ballet, he premiered roles such as Billy in Zoe Henrot’s To Billy and Escamillo in Carmen. During his time with Minnesota Ballet he performed multiple lead roles in ballets by choreographers such as Robert Gardner and Salvatore Aiello.