The former refugee, 31, played for Australia A last month in England and selector John Inverarity has indicated he will be considered for the Ashes squad.
Ahmed described his experience as "unbelievable".
"I still can't believe this and it's a great honour for me," he said.
"Now I am a citizen and now I can really concentrate on my cricket and can look to my bright future in cricket."
Ahmed returned home from England in June after the government moved a bill through the upper house of parliament to amend the Citizenship Act to help fast-track his application.
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Ahmed thanked the government for its support.
"I was happy from last year when I got my residency but it was still stressful because I wasn't officially a citizen," he said.
"It was a long journey... Thanks to minister... And the whole government of Australia, they really helped me. It was not an easy job to change the law."
Ahmed has been named in the Australia A squad for a tour of Africa beginning later this month, despite also being in contention for the Ashes.