According to Official Guinness Records,
The fastest half marathon in a suit (female) is 1 hr 42 min 42 sec and was achieved by Jennifer Wilson (Canada) at the 2016 Scotiabank Toronto Waterfront Marathon, in Toronto, Ontario, Canada, on 16 October 2016.This is Jennifer’s first ever record attempt and Guinness World Records title.
For a complete list of 2016 records, please visit 2016 Guinness Records in Canada.