|Jason Tam as Markko Rivera|
|One Life to Live|
|Portrayed by||Jason Tam|
|First appearance||May 21, 2007|
|Last appearance||January 13, 2012|
|Cause/reason||Moved to Los Angeles|
|Created by||Dena Higley|
|Introduced by||Frank Valentini|
|Residence||Los Angeles, California|
Markko appears in the gym of Llanview High School during tryouts for the school musical. Immediately annoyed by Markko, Langston Wilde challenges him to tryout, to which he does, and gets a part. During the prom, English teacher Marcie McBain gets ahead of herself, and announces Markko and Langston as king and queen of the dance. After prom night, Markko and Langston begin dating one another.
A few months into their relationship, Markko becomes concerned about the constant absence of Langston's parents. Sensing that something isn't right, Dorian Lord hires private investigator Rex Balsom to dig up information on Langston. Dorian learns that Langston has been orphaned, and living on her own for over a year. Langston can't believe that Dorian (great-aunt of Langston's best friend, Starr Manning) would pry into private information regarding her life. During a conversation at school, Langston talks with Starr about her parents' death, and they are overheard by fellow student Britney Jennings. Britney contacts Social Services, and Langston is horrified whenever she is placed in foster care. Starr's mother, Blair Cramer, is all set to become Langston's foster mother whenever she is called out of town. In turn, Dorian chooses to become Langston's guardian. After things are official, Langston moves into Dorian's home, and happly continues her relationship with Markko.
After Starr becomes pregnant with Cole's baby, she decides to have an abortion before Cole and her family learns about her pregnancy. At the last moment, Langston gives Cole the address to where Starr is. After convincing her to take the time to make the right decision, Cole and Starr return to Llanview. Cole soon makes plans to run away with Starr, and with Markko's help, they run off to Virginia Beach. Dorian finds Langston hiding a pregnancy book, and suspects that she is pregnant. Markko confirms Dorian's claims, but the truth about Starr soon comes out, leaving Markko off the hook.