Does light travel in a straight line? If so, does this contradict the fact that light is a wave?

It is commonly stated that light travels in a straight line in a homogeneous medium. However, light is also a kind of wave; waves oscillate and they do not travel in a straight line.

Do these two statements contradict each other?

Initially, I thought the statement "light travels in a straight line" was incorrect and light only appears to (but actually does not) travel in straight lines due to its extremely short wavelength, making the oscillations invisible to the human eye. However, after some research, I found that the statement is indeed considered correct.

light is also a kind of wave; waves oscillate and they do not travel in a straight line.

Electromagnetic waves (light) travel with an electric and magnetic field which are oscillating perpendicular to each other and perpendicular to the direction the light ray is traveling. It moves in a perfectly straight line (in free space with no gravitational fields) which can be defined by the Poynting vector $$\bf S=E\times \frac B \mu$$ i.e., the vector cross product of the electric and magnetic field vectors.

Do these two statements contradict each other?

No. Using the link that Ghoster included in their comment, it's important to note that the red and blue line represent the oscillation of electric and magnetic fields and not the physical movement of the light ray.

The straight-line direction of travel of the light ray is represented by the z-axis.

Light is a wave. Maxwell's equations tell you how the wave propagates. It can be curved.

Ray optics is an approximation. In most cases, it is a good approximation. Rays are lines perpendicular to the wave fronts. A point source of light emits spherical waves. The rays are straight lines that originate at the source. A plane wave has parallel rays. Ray optics is good enough to do most lens design.

If you solve Maxwell's equations for a laser cavity, you usually get a Gaussian beam. The rays follow hyperbolic paths. In the far field, they approximate a spreading cone. But the divergence angle is very small, typically a few milliradians.

Another place you might see bent light is if you pass a beam through a pinhole. This is called diffraction. You will also see it if light passes through a slit or near a single edge.

You can think of the aperture of a lens as a very large pinhole. This causes a small amount of diffration. Usually imperfections of the lens design or manufacture cause larger problems. But some (expensive) lenses are so well designed and made that diffraction is the biggest problem. These are said to be diffraction limited.

I think this is one of those situations where an animation is worth a thousand words:

Source: Wikimedia Commons

As you can see, at any given point the E and B fields are oscillating but the wave is still traveling in a straight line overall.

Light does not necessarily travel in straight lines although it frequently does or appears to. This is not a contradiction. In classical physics light is known to follow a path of least time. This is called Fermat's Principle.

Fermat's principle was initially controversial because it seemed to ascribe knowledge and intent to nature. Not until the 19th century was it understood that nature's ability to test alternative paths is merely a fundamental property of waves.

In modern times we consider light taking the path of least action. Light, as with all electromagnetic waves, can have its path distorted by all sorts of effects. The most popular is by strong gravitational fields.

One of the most relevant though is the atmospheric refraction of light which most definitely causes light to "bend" as it travels because of changes in atmospheric density and local composition.

Drop a pebble in a pond and the waves spread out in straight lines from the point of impact. That’s why you can see the ripples as expanding circles - straight lines away from a point form circles. The water molecules move up and down but the wave, and the energy, travel in straight lines.

The same is true of sound waves in air. Detonate a bomb in the air and the sound (pressure) waves travel away from the blast in straight lines. These are compression waves rather than transverse waves so the molecules move back and forth in the direction of the wave rather than perpendicular to it, but the wave itself moves in a straight line.

Same is true of a light wave. Turn on by measuring how long it takes to reach various distances, you can see it travels in a straight lines. Now, EM radiation is different from waves that propagate through a medium in that they consist of self-propagating electric and magnetic fields transverse to the direction of propagation but that doesn’t change the fact: all waves travel in straight lines.

1 In a uniform medium without obstructions. Also noting that “straight line” means shortest distance in the relevant geometry, which might not be flat.

It's worth mentioning General Relativity since you hear that "light curves". EM waves, ray optics, and quantum mechanics have been discussed already. When you consider General Relativity, mass and energy curve space and time (spacetime). Spacetime curvature is defined mathematically, but an intuitive understanding is pretty useful here. Think of a vortex you roll a marble or coin around. The path is like the path of light in curved spacetime. So the light is following the shortest path from start to finish. In that sense, light is following a straight line in a curved spacetime. In geometry, the shortest distance between two points is a straight line. (It is called a geodesic, especially when you consider curvature.) This is separate from refraction of light. In most situation, the curvature of spacetime can be ignored. However, with black holes and other extreme cases, you must consider spacetime curvature. In fact, spacetime curvature is the reason that black holes are "black". We see things because they emit or reflect light. Any light emitted or reflected by a black hole follows a path that never reaches us because the spacetime close to a black hole is so curved.