Teachers are found in every community and are essential to fulfilling the potential of every student. The teaching profession is large, with K-12 teachers comprising 3% of all jobs in the United States. And yet, what is known about the characteristics of teachers in the Milwaukee metro area? In this report, the author addresses this question with a comprehensive look at public school teachers in Greater Milwaukee. This analysis expands the scope of the K-12 reports to the four-county Milwaukee metropolitan area. It uses the most up-to-date data available to answer a number of questions, including: (1) How many teachers are there in Greater Milwaukee and how does that number compare among school districts? (2) What are the ages and demographics of the teaching workforce across the region? and (3) How do teacher qualifications and levels differ among different districts, and have there been significant changes over time? The teaching profession in Wisconsin has been the subject of much discussion and debate in recent years, particularly during consideration and implementation of Wisconsin Act 10. Consequently, this analysis includes data over multiple years to capture changes in teacher characteristics that have occurred since Act 10's adoption in 2011. [For the second report in this series, see ED570113. For the third report in this series, see ED570114.]