You can use PlotRange -> {Automatic, {1, All}}
.
An example:
SeedRandom[1]
data = RandomReal[100, {100, 2}];
data = Append[data, {{500, 50}, {50, 500}}];
Row[{ListPlot[data, ImageSize -> 300,
PlotLabel -> "PlotRange -> Automatic"],
ListPlot[data, ImageSize -> 300,
PlotRange -> All, PlotLabel -> "PlotRange->All"]
ListPlot[data, ImageSize -> 300,
PlotRange -> {Automatic, {70, All}},
PlotLabel -> "PlotRange -> {Automatic, {70, All}}" ]},
Spacer[20]]
This works in both directions. You can use PlotRange -> {Automatic, {All, 50}}
to have the vertical plot range go from the minimum of data to 50:
ListPlot[data, ImageSize -> 300,
PlotRange -> {Automatic, {All, 50}},
PlotLabel->"PlotRange -> {Automatic, {All, 50}}" ]