Holding pattern shape and terminology

Unless the clearance given by ATC (or the route documentation contains instructions to the contrary), all turns after initial entry into the holding pattern shall be made to the right.
Countries applying US regulations use the phrase ’standard pattern’ for a right-hand pattern, and ’non-standard pattern’ for a left-hand pattern.

Holding Pattern (right turns)

Source: ICAO

See also:
Approaching Holding fix

Entry into the Holding

Holding pattern shape and terminology

Standard limitations for Speed, Rate of turn and Timing (Holding)

Flying the Holding pattern – Wind correction
Leaving the Holding pattern

Protected airspace (Holding)