Not to be semantically confused with : Yellow Oxeye (Telekia speciosa) [a plant with similar name belonging to the same Dandelion & Daisy family but with very large bright-yellow but narrow ray-florets with very large cordate to lanceolate leaves]
Easily mis-identified as : Oxeye Daisy (Leucanthemum vulgare) but that is shorter at up to 75cm high has smaller flowers 25-60mm across, mostly roundly lobed but highly variable leaves, some with several auricles. The leaves basal leaves have long slightly-winged stems with a leaf shaped like a table-tennis bat, but either slightly toothed or roundly lobed.
Far fewer similarities to :
Autumn Oxeye (Leucanthemella uliginosum) which more closely resembles Shasta Daisy but the leaves lack the characteristic smell of that and are a paler green, are thinner and possess more sharply-pointed and deeply-serrated teeth. Autumn Oxeye is also almost unknown in the wild in the UK now, and, at up to 2m tall, is much taller than either Oxeye Daisy or Shasta Daisy.
The leaves smell something awful when crushed, and the flowers themselves, when gathered together, also pong. This plant is thought by many to be a hybrid between Leucanthemum lacustre and Leucanthemum maximum (both of which are native to France & Spain but neither of which are native to the UK). But rather than a hybrid it may be Leucanthemum lacustre itself. Sometimes Shasta Daisy is double-flowered.
Shasta Daisy has a disagreeable smell which some describe as a stench.