In the state assembly proceedings, Ahmad, 55, secured 21 votes out of 36, while the other candidate, Kedah PAS commissioner Ahmad Fakhruddin Syeikh Fakhrurazi, secured the remaining 15.
Kedah state assembly secretary Iqbal Ahmad made the announcement following the voting session.
Ahmad, who is from PKR, subsequently took his oath before the Kedah assembly.
The Pakatan Harapan (PH)-led Kedah government previously nominated Ahmad as its candidate, while Ahmad Fakhruddin was nominated by PAS.
The former Kedah PKR chairman had contested and won the Kuala Kedah parliamentary seat in the 12th general election (GE12) in 2008.
All 36 Kedah assemblymen took their oath in the state assembly today.
The issue of who would be speaker and deputy speaker had dragged on following PH’s May 9 election win in Kedah.
Kedah Menteri Besar Mukhriz Mahathir had reportedly expressed hope that the opposition assemblymen would accept PH’s choice of state assembly speaker.
The Jitra assemblyman was reported as saying that in the event that the house was equally divided, a vote from the Speaker would have to be considered.
He also said there was a likelihood of state elections if either proposed speaker was rejected by the other side.
In the recently concluded election, PH won 18 seats, one short of a simple majority of 19. The remaining seats were won by PAS (15 seats) and Barisan Nasional (three seats).
Mustahil calon luar PAS jadi speaker DUN Kedah, kata Mukhriz