In turn, Democrat Kathleen Drew came close to breaking a Republican grip on the secretary of state's office. Democrats have not produced a secretary of state in nearly 50 years.
Drew and Wyman were running to replace Republican Sam Reed, who is retiring. He was elected in 2000.
The secretary of state oversees state and local elections and registers and licenses private corporations.
Wyman led Drew with 51 percent of the vote Saturday. The race was one of the closest contests in the state.
"I called Kim Wyman to congratulate her on a hard fought victory and to concede the race. I know that she will carry forward Washington's tradition of fair and impartial elections, and I am optimistic that she will work on measures to remove barriers and increase voter participation," said Drew, a former state senator, in a statement.
Wyman is Thurston County's auditor.
Drew, who represented Seattle's eastern suburbs in the Legislature, wanted to change the way Washington registers voters. Her goal was to expand the number of people casting ballots by letting people register on Election Day and allowing 16- and 17-year olds to pre-register when they get their drivers' licenses.
Wyman had said Drew's plans won't work because Election Day registration would take finite resources away from counting ballots and delay the posting of results in Washington, a state notorious for the glacial pace of its election count.
Prior to this election, Republicans led the attorney general and secretary of state's office.
After two-time attorney general Rob McKenna unsuccessfully ran for governor, Democrat Bob Ferguson beat out Republican Reagan Dunn for the post.