Mark Wahlberg can now add high school graduate to his resume.

The actor and producer, who dropped out of school in the ninth grade, received his high school diploma in June through an online program and celebrated the milestone at an event for the Taco Bell Foundation for Teens in Irvine, Calif., on Monday.

"I was fortunate to find out I could attend high school online," Wahlberg, wrote in an op-ed on Huffington Post. "For almost a year, I've been taking classes and studying any chance I could get-on the set, traveling for work and at home. It has been both humbling and challenging, but I'm happy to report that I am officially a high school graduate."

The 42-year-old actor and father of four announced his plans to finish school in June 2012 during a visit to "The Late Show with David Letterman."

"They have this new program in Massachusetts where you can actually take the courses online, so I'm starting this month in New Orleans," Wahlberg said. "They're going to give me whatever credits I already have, which is probably like one or two, but I'm going to make it happen."

According to the Huffington Post, Wahlberg studied while filming "2 Guns," and kept it a secret from co-star Denzel Washington.

"Denzel was always asking me what I was doing but I didn't want to share that information with him," he told People. "Nobody knew, because I felt like I don't like to count my chickens before they hatch, so I didn't want to say that I was doing it until I actually finished it. What if I said I'm doing this and I didn't finish it?"

While at the event for the Taco Bell Foundation for Teens, Wahlberg presented scholarships to Taco Bell employees as part of its pilot program and make efforts expand the educational horizons.

"I was able to do it because I knew I wasn't alone, that other teens and adults were going through the same thing I was in balancing work and family in order to better themselves," Wahlberg wrote. "To those students struggling every day and those who are looking for a second chance, I have a message for you: never give up. Keep believing in yourselves and don't make small plans."

The actor said it was by luck that he ended up with a successful career in Hollywood after dropping out. But compared to most high school dropouts, many are unemployed, with poor health, living in poverty or on public assistance. He urged people not to reply on luck.

"It shouldn't take luck for people to be able to access the education they need to help overcome life's obstacles," he wrote. "Investment in education is a no-brainer in promoting personal and career growth and supporting our economic recovery."

Wahlberg has a busy schedule lined up, with "Ted 2" in the works and roles in "Transformers: Age of Extinction" and "Lone Survivor" coming up in 2014. Also his work as a producer on shows, including "Boardwalk Empire".