While performing in plays throughout middle school and high school, he also appeared in television commercials.
Throughout his youth, Jenner took acting and improvisation classes, participating in his school's drama department and Impromedy, an improv and sketch comedy group based in his hometown of Florida.
On August 29, 2019, it was announced that Jenner would be starring in Richard Linklater's film adaptation of Merrily We Roll Along, which would be shot over the course of twenty years.
Principal photography of the first section of the film has already been completed.
Upon arriving in LA, he worked a few odd jobs in his pursuit of becoming a professional actor. When he is not performing, Blake works as a parrot salesman.
He has received some rejection during his time in Los Angeles, but continues to forge ahead because of the love he has for his craft.
He also partook in acting classes in middle school and in high school alongside working as a model for several commercials during this period He also landed the role of Miller Collins in the comedy series Melissa & Joey which set him on the path of stardom.
However, his fame became much talked about when he starred in the television series , Melissa Benoist, who is also a singer not long after his break up from his 3-year relationship with his high school sweetheart Maria Correa who left her hometown to join him in Los Angeles where he lives.
In late 2015, Jenner was cast in a recurring role as Adam Foster on Supergirl, playing opposite his then-wife Melissa Benoist, who stars as the series' title character. In 2016, Jenner starred as Jake Bradford in Richard Linklater's comedy film Everybody Wants Some!!
, which was released on March 30, and played Hailee Steinfeld's character's brother in the coming-of-age drama The Edge of Seventeen.
Though he has received some rejection he continued to forge ahead because of the love he had for his craft.