Elections to the Indiana Senate took place on November 6, 2018. Primary elections were held on May 8, 2018. Summary of Results Source: Close races Two districts had a margin of victory under 10%: District 31, 2.8% District 25, 7.8% District 46, 9% Retiring incumbents Two incumbent Senators, both Republicans, chose to not seek reelection. Doug Eckerty (R), District 26 Jim Smith (R), District 45 Incumbents defeated In primary One incumbent Republican Senator ran for reelection but was defeated in the May 8 primary. Joe Zakas (R), District 11 Detailed Results Sources: District 1 Democratic primary Republican primary General election District 4 Democratic primary Republican primary General election District 6 Republican primary Democratic primary General election District 11 Republican primary Democratic primary General election District 14 Republican primary General election District 15 Republican primary Democratic primary General election District 17 Republican primary Democratic primary General election District 19 Republican primary General election District 21 Republican primary Democratic primary General election District 22 Republican primary Democratic primary General election District 23 Republican primary General election District 25 Democratic primary Republican primary General election District 26 Republican primary Democratic primary General election District 27 Republican primary Democratic primary General election District 29 Republican primary Democratic primary General election District 31 Republican primary Democratic primary General election District 38 Republican primary Democratic primary General election District 39 Republican primary General election District 41 Republican primary Democratic primary General election District 43 Republican primary General election District 45 Republican primary Democratic primary General election District 46 Republican primary Democratic primary General election District 47 Republican primary Democratic primary General election District 48 Republican primary General election District 49 Republican primary Democratic primary General election References 2018 Indiana elections Indiana State Senate Indiana Senate elections