A 17-percentage point surge since the last ARD-Germany Trend poll in December meant Steinmeier just pipped Merkel to the post.
Seventy percent of respondents said they were satisfied or very satisfied with how the Social Democrat (SPD) veteran was performing in his job as foreign minister, compared to 69 percent for Merkel.
Finance Minister Wolfgang Schäuble, from Merkel’s CDU party, occupied third place, as 68 percent of those polled said they were happy with his work.
Politicians from either side of the coalition shared fourth spot – Vice Chancellor Sigmar Gabriel (SPD) and Thomas de Maizière (CDU) each scored 49 percent.
Poll respondents were less pleased with the performances of Defence Minister Ursula von der Leyen, who fell six points to 43 points, while Horst Seehofer, the leader of the Christian Democrats’ Bavarian sister party, the CSU, plunged ten points to 38 percent.
Steinmeier, who served as foreign minister from 2005-09, has also been busy globetrotting in a sign Germany will pursue a more active foreign policy.