PKP class ST45

{{one source|date=December 2014}}

{{Infobox locomotive

|name = ST45

|powertype = Diesel

|image = ST45-01.jpg

|caption =

|builder = PESA Bydgoszcz
SU45s built by Cegielski

|serialnumber =

|buildmodel =

|builddate = 2009

|totalproduction =

|uicclass = Co′Co′

|gauge = {{track gauge|sg}}

|leadingdiameter =

|driverdiameter = 1,100 mm

|trailingdiameter =

|wheelbase =

|length = 18,990 mm

|width = 3,900 mm

|height = 4,288 mm

|frametype =

|weightondrivers =

|locoweight =

|locotenderweight =

|fueltype =

|fuelcap =

|tendercap =

|consumption =

|watercons =

|electricsystem =

|collectionmethod =

|primemover =

|enginetype = MTU 4000

|displacement =

|boiler =

|boilerpressure =

|feedwaterheater =

|firearea =

|tubearea =

|fluearea =

|tubesandflues =

|fireboxarea =

|totalsurface =

|superheatertype =

|superheaterarea =

|cylindercount = 12

|cylindersize =

|rearcylindersize =

|hpcylindersize =

|lpcylindersize =

|valvegear =

|transmission = Electric

|maxspeed = {{cvt|120|km/h|round=5}}

|poweroutput = {{convert|1500|kW|bhp}}

|tractiveeffort =

|factorofadhesion =

|locobrakes = Oerlikon

|trainbrakes =

|operator = PKP

|operatorclass = ST45

|numinclass = 4

|fleetnumbers = ST45-01—ST45-04

|officialname =

|nicknames =

|locale =

|deliverydate = 2009

|firstrundate =

|lastrundate =

|retiredate =

|restoredate =

|scrapdate =

|currentowner =

|disposition =

}}

ST45 is the name for a Polish diesel locomotive. They are freight only locomotives, having had their train heating removed.