| Mia Costello | |
| State House: | Alaska |
| District: | 15th |
| Term Start: | January 21, 2025 |
| Succeeding: | Tom McKay |
| Office1: | Majority Leader of the Alaska Senate |
| Term Start1: | January 15, 2019 |
| Term End1: | July 8, 2019 |
| Predecessor1: | Peter Micciche |
| Successor1: | Lyman Hoffman |
| State Senate2: | Alaska |
| District2: | K |
| Term Start2: | January 20, 2015 |
| Term End2: | January 17, 2023 |
| Predecessor2: | Lesil McGuire |
| State House3: | Alaska |
| District3: | 27th |
| Term Start3: | January 18, 2011 |
| Term End3: | January 20, 2015 |
| Predecessor3: | Bob Buch |
| Successor3: | Mike Hawker |
| Birth Date: | 11 January 1968 |
| Birth Place: | Anchorage, Alaska, U.S. |
| Party: | Republican |
| Spouse: | Andrew Billings |
| Education: | Harvard University (BA) University of Alaska, Southeast (MA) |
| Website: | https://www.votemia.com/ |
Mia C. Costello (born January 11, 1968)[1] is a Republican politician from Alaska. She was member of the Alaska Senate from District K. She previously served from 2011 to 2015 in the Alaska House of Representatives, representing the 20th District.
In November 2010, Costello defeated Democratic incumbent Bob Buch to win her House seat. Costello received 3,696 votes to Buch's 2,873.[2] Costello served on the House Finance Committee and as chair of the Natural Resources Finance Subcommittee. She ran for the Senate seat vacated by Democrat Hollis French in 2014, picking up the seat to add to the Republican Senate Majority.[3]
Prior to being elected to the Alaska State House, Costello worked as a school teacher, legislative aide, and as deputy communications director for Governor Frank Murkowski.[4]
After graduating from West High School, she earned her B.A. from Harvard University and later a Master of Art in Teaching from the University of Alaska Southeast.[5]
In the 2024 Alaska House of Representatives election, she was elected in District 15.[6]