Katherine McGregor
Katherine McGregor (or similar) may refer to:

Actors
Katherine MacGregor (1925–2018), American actress a/k/a Scottie MacGregor
Kate McGregor-Stewart (born 1944), American actress in Wonder Park
Kate McGregor (born 1972), English actress known for Emmerdale

Others
Cathy McGregor (born 1955), Canadian legislator in British Columbia 
Cate McGregor (born 1956), Australian transgender writer and commentator
Catherine MacGregor (born 1972), French business executive
Katie McGregor (born 1977), American long distance runner
Katharine MacGregor, American public official since 2000s
Kate MacGregor (born 1991), English Olympic competitor in sailing

Characters
Kate "XO" McGregor, played by Lisa McCune on 2007 Australian TV drama Sea Patrol