Alec Mazo is a Russian-born American professional ballroom dancer based in San Francisco. He is well known for his participation in Season 1 of the US Dancing with the Stars, coming in first place with partner Kelly Monaco.

Mazo has been dancing since he was five years old, and moved to America from Russia with his family at age 12. He grew up in San Antonio, Texas and is of Russian Jewish descent. His mother ran a dance studio, and today Alec runs the largest youth ballroom dance school in California.

Alec attended UC Berkeley and received a BA in Cognitive Science. He has appeared in the Vanessa Williams movie Dance With Me as well as numerous commercials.

Alec and his partner Edyta Sliwinska only turned professional in the last few years, having been successful amateur Latin competitors for the five years before. Alec says he is a very dominant, powerful male on the dance floor. He uses his good looks and admits that he concentrates on the aesthetic side of the performance because he knows that's what he's good at.

Alec and Edyta married on September 1,2007. They have performed together on several results shows of Dancing with the Stars.

Alec returned to the ballroom on March 19 for Season 4, this time partnered with former supermodel Paulina Porizkova, but were the first couple eliminated.