Caleb Stan Ralph (born 10 September 1977 in Rotorua) is a New Zealand rugby union footballer.

Ralph began his first-class career with Bay of Plenty, then moved to Auckland before heading to Canterbury.

He started his Super Rugby career with the Chiefs in 1997, Blues (1998–1999), Crusaders (2000–2008) and a cameo role with the Queensland Reds (2011).

The following year in the final round of the regular 2011 Super Rugby season, Queensland Reds coach Ewen McKenzie recruited Ralph on a short term contract to combat the side's injury crisis in the outside backs.

In Round 18 he took the field in the 65th minute as a substitute and equalled George Gregan's then-record of 136 Super Rugby games.