The 2007 elections, in which she stood in the Reykjavík North constituency, saw the return of the Social Democratic Alliance to government in coalition with the Independence Party, and Jóhanna was named Minister of Social Affairs and Social Security.
Izbori 2007. godine, na kojima se kandidirala u izbornoj jedinici Reykjavík-Sjever, donijeli su povratak Socijaldemokratskog saveza na vlast u koaliciji s Nezavisnom strankom, zbog čega je Jóhanna imenovana ministricom za socijalna pitanja i socijalnu sigurnost.